System Design Questions
665 comprehensive questions across 12 categories
Showing 665 questions
Design Twitter Timeline
Handle massive user feed with real-time updates and ranking; optimize for writes and near-instant reads.
Design Instagram Feed
Photo-sharing with infinite scrolling, caching, and personalized content ranking.
Design Facebook News Feed
Manage friend networks, content relevance algorithms, and high-scale read/write across billions.
Design LinkedIn Feed
Professional connections, role-based recommendations, content filtering for recruiters vs job seekers.
Design TikTok Recommendation Engine
Short videos, user interaction signals, and advanced recommendation with ultra-low latency.
Design Reddit
Forum-based site with sub-communities, upvote/downvote mechanisms, and time-based ranking.
Design Pinterest
Image-heavy boards, infinite scrolling, sophisticated search, and quick data retrieval.
Design Quora
Q&A platform with question-topic mapping, user reputation systems, and content retrieval.
Design Clubhouse
Real-time audio rooms, ephemeral sessions, user invites, and concurrency at scale.
Design Snapchat Stories
Ephemeral media, direct messaging, short-lived content, and real-time friend presence.
Design Slack Channels
Real-time messaging with channels, threads, presence indicators, and enterprise compliance.
Design Discord
Real-time voice, text, community servers, large concurrency, and role-based permissioning.
Design Bumble or Tinder
Match users based on location/preferences; concurrency, recommendation logic, and swiping.
Design Real-Time Event Feed
Ingest high-frequency data from multiple sources; broadcast user-specific events with minimal delay.
Design Social Graph Analysis
Manage relationships, find mutual connections, and run BFS/graph algorithms on billions of edges.
Design Twitter Spaces
Real-time audio conversations for large audiences with easy creation/discovery.
Design Hashtag Aggregator
Index trending tags, unify results across services, and handle traffic spikes.
Design Nextdoor
Neighborhood-based network requiring address verification and localized feed distribution.
Design Meetup
Organize events by location/topic, manage RSVPs, and suggest relevant groups.
Design Social Presence Service
Show who is online/active, track device connectivity, and broadcast real-time status.
Design Community Forum with Upvotes
Traditional thread-based community with point system; optimize for engagement.
Design Real-Time Polling Platform
Collect instant votes, see dynamic results, handle spiky loads, and ensure fairness.
Design Activity Stream
Aggregate user actions (follows, likes, comments), store and deliver personalized timelines.
Design Online Debate Platform
Structured debate threads with pro/con voting, user reputations, and large text submissions.
Design Follower-Following System
Manage user relationship graphs, quick follow/unfollow writes, and near real-time feed updates.
Design Trending Topics Service
Calculate hashtag velocity, track location-based trends, and handle high-volume queries.
Design Social Recommendation System
Suggest new friends/topics via collaborative filtering and graph-based affinity scoring.
Design Livestream Chat Service
Real-time text flow for thousands of concurrent viewers, plus ephemeral or replayable logs.
Design Multi-Language Social Platform
Handle i18n, content translation, region-based policies, and multi-lingual search indexing.
Design Alumni Networking Platform
Manage .edu verification, graduation year grouping, and specialized job postings.
Design Social Marketplace
Mix social features with e-commerce (likes, shares, listings); handle transactions.
Design Hobby Group Aggregator
Let users discover niche communities; track interest-based subgroups and events.
Design Social Q&A Board
Mini-Quora style focusing on short answers, upvotes, and topic categorization.
Design Endorsements System
Tag user skills, track endorsements, boost credibility, and rank profiles in search.
Design 1-1 Chat in Social Platform
Integrate ephemeral or permanent messaging, read receipts, and push notifications.
Design Mentions Service
Tag and notify users when mentioned in real time, handle spam detection.
Design Content Moderation Pipeline
Automate text/image/video scanning for policy violations; queue for manual review.
Design Anti-Spam Service
Real-time classification of bad content, integrate ML pipelines, propagate blocklists.
Design Social Games/Leaderboards
Track user scores, handle concurrency, store seasonal results, prevent cheating.
Design Event Invitations & RSVPs
Manage large invitation distribution, reminders, and real-time guest count updates.
Design Facebook Groups
Community creation, role-based permissions, pinned announcements, membership management.
Design Real-Time Reaction Stream
Let watchers send emojis on live content; queue and broadcast instantly.
Design Social Gifting Feature
Virtual gifting via coins/tokens, track gift redemption, handle suspicious transactions.
Design Private Family Network
Invite-only membership, secure photo sharing, generational grouping.
Design Auto Tagging / Face Recognition
Use ML for face detection in images, tag recognized users, store metadata securely.
Design Profile Verification System
Confirm identity with docs or selfies; track verification levels, reduce fake accounts.
Design Social Commerce Livestream
Combine real-time video with interactive buy buttons, comments, and transaction backend.
Design Social Search
Index posts, profiles, hashtags; handle typos, synonyms, and real-time indexing.
Design Memories/On This Day
Surface old posts by date, handle privacy for tagged users, and optimize storage retrieval.
Design Creator Analytics Dashboard
Track engagement metrics, follower growth, content performance for creators.
Design a 1-1 Chat Within a Social Platform
Design a durable, real-time, private 1-1 messaging system: per-conversation sequencing, cursor sync, push pipeline, media lifecycle, E2EE options, and trust-and-safety at scale.
Design an Activity Stream for Social Apps
Design a scalable activity stream with event capture, hybrid fanout, grouping, ranked feeds, and real-time updates at social scale.
Design an Auto Tagging / Face Recognition Feature
Design a production face-recognition auto-tagging pipeline with async ML inference, Faiss vector search, biometric consent, and GDPR/BIPA compliance.
Design a Birthday Reminder & Celebration System
Design a timezone-correct, privacy-first birthday reminder and celebration system with day-sharded indexing, idempotent fan-out, dedup ledgers, and consent-gated monetization.
Design a College Alumni Networking Platform
Design a verified, privacy-aware alumni networking platform with identity verification, class-year cohorts, mentorship matching, directory search, and moderation at scale.
Design a Community Forum with Upvotes
Master the community forum system design interview: hot-counter voting at scale, Reddit-style ranking algorithms, threaded discussions, reputation systems, and anti-brigade moderation with real cas...
Design a Content Moderation Pipeline
Design a production content moderation pipeline: bounded sync gate, hash-first async cascade, precision-gated auto-enforcement, leased human review with wellbeing caps, tombstone fan-out, appeals, ...
Design a Distributed Anti-Spam Service
Design a multi-surface anti-spam platform with inline decisions under 50 ms, async deep classification, reputation scoring, campaign containment, and governed policy releases.
Design an Event Invitations & RSVPs System
Design a scalable event invitations and RSVPs platform with fan-out engines, seat ledgers, tiered tallies, durable reminder scheduling, waitlists, and calendar integration across AWS, GCP, and Azure.
Design a Facebook Groups Alternative
Design a governed community platform with hybrid fan-out, role-based governance, membership approvals, pinned announcements, notifications, within-group search, and capacity-planned moderation at 2...
Design a Follower-Following System
Design a billion-edge social follow graph: dual-indexed transactional edges, cache-first reads, celebrity hot-key isolation, reconciled counts, fail-closed privacy, hybrid fan-out, and real-time su...
Design a High-Frequency Mentions Service
Design a real-time mentions and notification pipeline with extraction, abuse-resistant fan-out, aggregation, badge caching, and multi-cloud scale.
Design a Hobby Group Aggregator
Design a discovery-first platform that aggregates millions of hobby micro-communities: hybrid fanout, geo search, recommendations, RSVP capacity, and scalable moderation.
Design a LinkedIn Endorsements System
Design a scalable skill endorsement platform with event-driven count aggregation, suggestion engine, and trust-and-safety at LinkedIn scale.
Design a Multi-Language Social Platform
Design a global multi-language social platform with UI localization, content translation, language detection, multilingual search, feed preferences, caching, and regional compliance.
Design an Online Debate Platform
Design a structured debate platform with argument trees, timed rounds, voting integrity, reputation, moderation, live fan-out, search, and archival at social scale.
Design a Private Social Network for Families
Design an invite-only family platform with capability-based media access, per-family envelope encryption, cycle-safe genealogy, child-safety policy, and proven multi-decade durability.
Design a Profile Verification System
Design a profile verification platform with document forensics, liveness and face matching, tiered badges, and privacy-first retention.
Design a Real-Time Polling Platform
Design a real-time polling platform with durable vote ledgers, layered double-vote prevention, sharded hot tallies, coalesced WebSocket fan-out, scheduled expiration, and fenced close reconciliatio...
Design a Real-Time Reaction/Emoji Stream
Design a live reaction stream with edge tap shaping, windowed aggregation, connection-local fan-out, floating overlay synthesis, replay correlation, rate limiting, and privacy at million-viewer scale.
Design a Social Platform for Audio Books & Clubs
Design a social audiobook platform with DRM-protected streaming, offline listening, book clubs, chapter-anchored discussions with spoiler gating, voice notes, listen-along sync, and multi-cloud scale.
Design Social Games/Leaderboards
Design a real-time social gamification platform with leaderboards, achievements, anti-cheat, and friend-scoped rankings at 10M DAU scale.
Design a Social Gifting Feature
Design virtual gifting at scale: double-entry coin wallet, idempotent sends, live overlay fan-out, notifications, payments, fraud prevention, refunds, and holiday surge capacity across AWS, GCP, an...
Design Social Graph Analysis
Design a planet-scale social graph with source-partitioned edge storage, caching, mutual friends, shortest path, and People You May Know.
Design a Social Marketplace for Products
Design a social marketplace with feeds, single-unit listings, negotiation messaging, protected payments, search, and trust-and-safety at scale.
Design a Social Media Hashtag Aggregator
Design a cross-platform hashtag trending system: multi-source ingestion, canonicalization, two-tier counting, burst scoring, compiled trend lists, caching, and graceful degradation.
Design a Social “Memories” (Lookback) Feature
Design Facebook-style On This Day memories: month-day partitioned historical scanning, timezone-sliced bundle generation, fail-closed privacy re-validation, ML ranking with wellbeing guardrails, an...
Design a Social Presence Service
Design a planet-scale social presence service: multi-device sessions, real-time online/idle/offline propagation, last-seen with privacy coarsening, push-notification reachability, flap-free failove...
Design a Social Recommendation System
Design a Social Recommendation System: architecture, trade-offs and scaling considerations.
Design Bumble or Tinder
Design a location-based dating platform with geo-fenced discovery, real-time match detection, swipe processing, WebSocket messaging, and privacy-preserving architecture.
Design a Trending Topics Service
Design a real-time trending topics service with stream processing, Count-Min Sketch, velocity scoring, spam detection, and multi-cloud architecture.
Design an Amazon-Like Online Store
You must build a massive e-commerce platform reminiscent of Amazon, featuring unlimited product catalogs, user session management...
Design a Shopping Cart Service
You need a microservice (or service) that stores, updates, and retrieves user carts.
Design a Payment Gateway (Stripe/PayPal-like)
Design an online payment service that securely processes credit card or bank transactions, issues tokens, manages refunds, and...
Design an E-Commerce Recommendation Engine
A system that suggests relevant products based on user behavior, item similarity, trending data, and user demographics.
Design a Flash Sales Platform
Build a system that runs limited-time or limited-inventory sales, often with tens of thousands of requests per second.
Design a High-Speed Product Search
Implement a robust search engine that can handle millions of SKUs, auto-complete suggestions, filtering by attributes, synonyms, and...
Design a Global Inventory Tracking
Create a system to track inventory levels across multiple locations.
Design an Auction or Bidding System (eBay-like)
Build an online marketplace for items with time-based auctions.
Design an Order Fulfillment Pipeline
Create a pipeline that moves orders from “placed” to “shipped” to “delivered.” Integrate warehouse picking, packaging, label printing...
Design a Shopping Festival (Prime Day) Scenario
Plan and execute a multi-day or day-long shopping festival with massive concurrent user traffic, special deals, dynamic pricing...
Design a Returns & Refunds Service
Create a system to manage user-initiated returns: label generation, condition checks (if needed), partial or full refund issuance...
Design an E-Commerce Chatbot
Build a conversational chatbot that helps users find products, answer shipping queries, handle returns, or even propose relevant...
Design a Warehouse Robot Coordination System
Robots retrieve items from shelves, avoid collisions, and deliver to packing stations.
Design a Payment Dispute & Chargeback System
Provide a platform to handle payment disputes or chargebacks initiated by customers or banks, gather evidence (receipts, shipping...
Design a Loyalty & Rewards Program
A system that tracks user spending, awards points for purchases, and offers redemption options or tier levels (Silver, Gold, Platinum).
Design a Multi-Currency Checkout
Enhance your platform to let users pay in their local currency, reflect real-time or daily updated exchange rates, handle rounding...
Design a Fraud Detection Microservice
Users place orders.
Design a Supplier & Vendor Portal
Vendors can create or update product listings, track sales, manage stock, and view payments.
Design a Multi-Tenant E-Commerce Platform
One core platform that spawns distinct “child” e-commerce sites for different merchants, each with unique branding, product catalogs...
Design a Reorder & Subscription Service
Allow customers to automatically reorder items (e.g., groceries, pet supplies) on a set schedule.
Design a Reviews & Ratings System
Enable users to post reviews & star ratings on purchased products.
Design a Price Watching Tool
Users follow certain products and get notifications if the price drops below a threshold.
Design a Multi-Warehouse Shipping Optimizer
When an order arrives, the system chooses the best warehouse to fulfill each item.
Design an E-Commerce Analytics Dashboard
A dashboard where admins or business owners see real-time or near real-time stats: revenue, top-sellers, abandoned carts, regional...
Design a Cross-Border Fulfillment System
A system that can handle cross-border shipping, customs forms, duties/taxes, and potentially region-based returns or local distribution...
Design a Mobile-First E-Commerce Experience
Focus on smartphone-optimized performance, with quick load times, offline browsing for product pages, minimal bandwidth usage, and...
Design a Real-Time Customer Support System
Provide real-time customer support channels (live chat, possibly voice/video).
Design a Search Query Auto-Correction
Enhance product search with automatic correction for user-typed queries (typos, synonyms).
Design a "Buy Now, Pay Later" Service
Allow customers to break a purchase into several installments, pay over time, and track each partial payment.
Design a Referral & Affiliate System
Users or external partners share unique referral links or codes.
Design a Coupon/Promo Code System
Enable users to apply discount codes or promos at checkout.
Design a Wishlist & Gift Registry
Users save items for later in a personal wishlist or create a public gift registry that others can purchase from.
Design a Recommender for Bundled Products
Suggest product bundles often bought together (e.g., laptop + mouse + carry case).
Design a Personal Shopper Chat Feature
Provide a live messaging or AI-based channel for style advice or product curation.
Design a Category Tree & Navigation
Create a hierarchical category system for browsing.
Design a Gift Card & Store Credit System
Users can purchase gift cards, and recipients can redeem them for store credit.
Design a Book Store with E-Book Delivery
Users purchase e-books.
Design a 'Store Pickup' Feature
Let users purchase products online, then pick them up from a chosen store location.
Design a Virtual Try-On / AR Commerce Platform
Allow users to virtually “try on” products (clothing, makeup, glasses) using their phone camera or AR.
Design an Invoice & Billing System
Automate invoice creation for each order, handle line items, taxes, shipping fees, possible partial payments, and store these records...
Design a Seasonal or Themed Storefront
Allow marketing or admin teams to quickly switch the e-commerce site’s theme, banners, and featured products for events like Black...
Design a Pre-Order System
Users reserve upcoming products before official release.
Design a Crowd-Funded Product Platform
Users pledge money to a project.
Design a Digital Coupons Aggregator
Collect and index coupon codes from various retailers or affiliate networks, let users search or apply them, possibly auto-inject codes...
Design an E-Commerce Chat Forum
An internal forum or community Q&A for customers to discuss products, share tips, and help each other.
Design a Global Drop-Shipping Network
When a user orders, the system automatically forwards details to a drop-ship partner who ships from their location.
Design a Returnless Refund Flow
For certain cheap or bulky items, the system automatically processes a refund without a return.
Design a One-Click Checkout
Users skip the usual cart + address + payment details, storing a default shipping & payment method.
Design a Gift Wrapping & Personalization Service
Customers add gift-wrap or personalized notes when checking out.
Design a Group-Buy Discount Feature
When a group of users collectively purchases an item, the price is discounted.
Design WhatsApp
Build a mobile-first chat application offering real-time text, media transfers, group chats, read receipts, and device-to-device encryption.
Design Slack
A workspace-centric communication platform with channels (public/private), direct messages, real-time presence, file sharing, and...
Design Zoom
Create a cloud-based HD video-conferencing platform that handles dynamic bandwidth adaptation, chat, screen share, breakout rooms, and...
Design Google Meet
A real-time video platform for scheduled or ad-hoc meetings, accessible via browser (no special install), with optional screen sharing...
Design WebRTC-Based Chat
Allow browsers to establish direct audio/video chat or data channels with minimal server overhead for relay.
Design a Push Notification Service
Design a service that stores device tokens, manages push credentials for iOS/Android, and fanning out messages in near real-time (e.g.
Design a Real-Time Collaboration Doc (Google Docs)
A web-based doc editor that lets multiple users type simultaneously with near-instant updates.
Design Microsoft Teams
Build a corporate communication platform that integrates text channels, video calls, file collaboration (SharePoint), real-time...
Design a High-Throughput Pub/Sub System
Construct a distributed system for high-volume event distribution.
Design a Real-Time Collaborative Coding Tool
A web-based environment where multiple developers can simultaneously edit code in real time, run or debug in a shared sandbox, highlight...
Design a Live Translation Chat App
Users chat in their own languages; the system auto-detects and translates messages in real time, showing each participant the content in...
Design a Broadcasting Alert System
Admins trigger an alert that fans out to a large subscriber base—possibly thousands or millions of recipients in real-time—through...
Design a Gaming Voice Chat (Xbox Live)
Console gamers join voice channels or squads, with live voice streaming.
Design a Town-Hall Webinar Platform
Host a live town-hall session for thousands of employees or participants.
Design a Real-Time Stock Ticker & Chat
Displays up-to-date stock quotes, with optional chat rooms for traders or watchers to discuss.
Design an Event RSVP & Live Updates
Let event organizers post an invitation link.
Design a Customer Support Chat
A web-based support channel for customers to chat with agents, see past conversations, attach files, and reference order data.
Design a Customer Support Voice IVR
An automated phone system where callers navigate via voice or keypress.
Design a Virtual Call Center
Central hub that queues inbound calls/chats, routes them to available remote agents based on skill sets or load balancing, and provides...
Design a Telemedicine Video Chat
Enable patients to consult doctors via real-time video.
Design a Live Data Visualizer
Users open a dashboard that receives a constant stream of data from external sources (IoT sensors, event logs).
Design a Real-Time Interactive Classroom
A virtual classroom where a teacher broadcasts audio/video, shares slides or a whiteboard, can see student activity (hand raises), and...
Design a 'Watch Together' Video Chat
Multiple users watch the same video simultaneously, with play/pause controls that apply to all participants in real time.
Design a Multi-User VR Chat
Users join a shared 3D space as avatars, talk in real-time with spatial audio, see each other’s movements, possibly manipulate virtual...
Design a Chatbot-Enhanced Live Chat
A chat platform where users first interact with a bot (maybe NLP-based).
Design an Event-Driven Notification Hub
Users sign up for various event topics; when events occur, the system routes them to web push, mobile push, or in-app notifications.
Design a Sports Score & Live Chat
Display real-time sports updates (scores, game clock) and allow fans to chat about the match.
Design a Massive Webinar with Real-Time Q&A
A large-scale webinar system where a host speaks/presents to thousands of attendees, who can ask text questions or answer live polls.
Design a Language Exchange Pairing App
Users sign up with their native and target languages, the system matches them with complementary partners for real-time calls or text...
Design a Hybrid P2P & Cloud Chat
Attempt direct peer-to-peer connections for user messaging or calls to minimize server overhead.
Design an Ephemeral "Chat & Disappear" App
A messaging service where texts or images vanish after being read or after a set timer.
Design a Multi-Party Audio Conference
Allow multiple participants to dial in or connect via VoIP to a shared audio-only conference.
Design a Psychic Reading or Hotline Chat
Customers pay to chat with “psychics” or experts in real-time.
Design a Smart Contact Center with AI Assist
An AI-enhanced system that listens (speech-to-text) or reads chat in real time, suggests possible answers from a knowledge base or next...
Design a Crypto Trader Chat
Traders chat about crypto markets in real time, see live price updates from multiple exchanges, possibly share signals or quick trades...
Design a Location-Based "Proximity Chat"
Users see or join a chat room if they’re within a certain radius or geofence.
Design a Live “Hints & Tips” Chat Overlay
Users run an app (e.g., a coding practice or a puzzle game) that shows a “Hints & Tips” chat overlay.
Design a Gaming Guild Chat
In-game text chat for guild/clan members.
Design a Stock Trading Collaboration Chat
A chat environment for professional trading desks or analysts to share ideas, run quick calculations, reference real-time quotes, and...
Design an Anonymous Confession/Support Chat
Users post confessions or need emotional support.
Design a Polling or Voting Chat
In a real-time group chat, participants can create polls.
Design a HR Interview Scheduling & Chat
Recruiters and candidates set up interview times, confirm with each other, and optionally chat in real time for clarifications.
Design a Live Audience Reaction for TV
Viewers tap reaction buttons on a mobile app while watching a live show.
Design a Disaster Alert & Communication System
Authorities issue emergency alerts targeted by region.
Design a Telepresence Robot Control
Users connect to a physical robot with camera, microphone, and wheels.
Design a Cross-Platform Chat Using MQTT
A chat system that employs MQTT for message distribution (topic-based or one-to-one).
Design a Walkie-Talkie Style Push-to-Talk App
Mobile or web app mimicking a physical walkie-talkie: one user at a time holds the “speaking floor.” Audio is broadcast to the entire...
Design a Live Whiteboard Session
Multiple participants draw or annotate on a shared canvas in real time.
Design a Real-Time Auction Chat
Users gather in a chat environment linked to a live auction.
Design an IoT Device Control Panel
A console for monitoring and sending commands to numerous IoT devices (smart lights, thermostats, sensors).
Design a Real-Time Analytics Pipeline
Construct a pipeline that ingests high-velocity data (e.g., logs, clickstreams), processes in near real time (aggregations...
Design a Data Warehouse (Snowflake/BigQuery)
A system optimized for analytical (OLAP) queries over massive structured/semi-structured data.
Design a Log Analytics Platform (Splunk-like)
A platform to ingest, parse, and index massive logs from various sources.
Design an Ad Click-Through Tracking System
Collect user clicks from ads, match them to impressions, and generate real-time or near real-time dashboards for advertisers.
Design a Recommendation ML Pipeline
Build a pipeline that ingests user-event data (clicks, views, purchases), transforms them into ML features, periodically retrains a...
Design a Data Pipeline with Kafka & Spark
Use Kafka as the ingestion backbone for high-throughput event data.
Design a Data Governance & Lineage System
Implement a system that catalogs all datasets, tracks transformations (ETL pipelines), clarifies ownership, and ensures compliance...
Design a Fraud Analytics Engine
Identify suspicious patterns in financial transactions or user activities.
Design a Data Lake (Hadoop/S3)
Store large volumes of raw data (logs, CSV, JSON, etc.) in a distributed file system or object store.
Design a Real-Time Leaderboard Analytics
Maintain a live, updated leaderboard for millions of users or players.
Design a Data Quality Validation Framework
Implement a system that checks incoming or batch data for validation errors or anomalies.
Design a Session Analysis & Heatmap Tool
Record user interactions on websites (cursor moves, clicks, scrolls), store sessions, and create heatmaps or funnel analyses.
Design a Predictive Maintenance System
Sensors stream temperature, vibration, or usage data from machines.
Design a Web Analytics Tracker (Google Analytics-like)
A snippet on each webpage sends events (page load, custom event) to a data collector.
Design a Cohort Analysis Platform
Group users by a shared start event (e.g., sign-up week), track their retention or behavior over subsequent periods (days/weeks).
Design a Stream-Processing ML Feature Extraction
Incoming events require on-the-fly feature generation (counts, last N event patterns, session stats).
Design a Distributed OLAP Cube
Pre-compute aggregates (sums, counts, averages) by various dimensions (time, region, product) for lightning-fast analytics.
Design a Recommendation Feedback Loop
Collect user actions (did they click recommended item? skip?), feed that data back into the recommendation pipeline.
Design an IoT Analytics Platform
Collect sensor readings from thousands or millions of devices, transform or aggregate them (e.g., average temperature, anomaly...
Design a Multi-Region Data Replication Strategy
Set up a system where data ingested in multiple geographic locations is replicated to a central or distributed cluster for analytics...
Design a Data Privacy & Compliance Masking Service
Intercept or transform sensitive columns (PII, protected health info) with anonymization, tokenization, or encryption.
Design a Reporting & Scheduled Jobs Framework
Users define recurring queries or analytics scripts.
Design a Business Intelligence "Self-Service" Tool
A web-based platform where business users can explore data, join tables, create visualizations, pivot charts, etc., all without writing...
Design a Cross-Platform Gaming Analytics
A gaming analytics system that ingests events from multiple platforms.
Design a Predictive Alert System (Spam/Abuse)
Ingest user activities (posts, messages, login patterns), run anomaly detection or ML classification to predict potential spam or abuse.
Design a Dedicated Feature Store for ML
A repository where ML features are consistently stored, updated, and served to both training pipelines (batch) and real-time inference...
Design a Query Suggestion & Autocomplete for Analytics
A system that tracks metadata (table schemas, column types, popular queries) and suggests partial or complete queries as the user types...
Design a MLOps Pipeline
Automate the entire ML lifecycle: from data ingestion, feature engineering, training, offline validation, to model packaging and...
Design a Large-Scale Email Campaign Metrics Tracker
After sending bulk emails, the system collects open/click events, unsubscribes, bounces in near real-time.
Design a Financial Trading Backtest System
Load historical price ticks or order book data, simulate trading strategies over that timeframe, track P&L, drawdowns, or risk metrics.
Design a Data Retention & Archival Workflow
Automatically move older data from hot (fast, expensive) storage to cold or archival layers (cheaper, slower) after a certain age...
Design a Recommendation A/B Testing Manager
Admin can create experiments comparing multiple recommendation models or parameter sets.
Design a Realtime NLP Pipeline
Messages arrive from a high-volume feed.
Design a Massive Graph Database for E-Commerce
Represent users, brands, and product categories as nodes, edges for relationships (purchases, brand tags).
Design a Geospatial Analytics Platform
Collect location-based data (e.g., driver pings, store locations), run queries like “all events within X km in last Y hours,” or...
Design a Voice Command Analytics Tool
Users speak commands to a device, which transcribes them.
Design an Ad Inventory Forecasting System
Given historical impression data and current traffic patterns, predict how many ad impressions can be served in upcoming days/weeks...
Design a Data Anomaly Detection Pipeline
A pipeline ingesting metrics or logs, applying real-time or batch-based anomaly detection methods.
Design a Data Consistency Checker for ETL Pipelines
After each ETL run, compare source vs.
Design a Data Pipeline for Genomics Analysis
Manage ingestion of raw DNA sequencing data (FASTQ, BAM), store it, run variant calling or other analytics in HPC or distributed...
Design a Satellite Imagery Analytics Workflow
Ingest raw satellite images, store them (maybe in a tile-based approach), run batch or streaming classification (e.g., detecting...
Design a Real-Time Document Processing & Extraction
Automatically process incoming documents (contracts, invoices).
Design an IoT Fleet Monitoring & Analytics
Track thousands of vehicles or devices, receiving location/telemetry.
Design a Centralized Metadata & Schema Registry
A system that stores schema definitions for multiple data streams/tables, tracks version changes, provides compatibility checks, and...
Design a ML Model Monitoring & Drift Detection
Continuously track model input distributions vs.
Design a Large-Scale Financial Market Data Lake
A central repository for all intraday trades, quotes, order book snapshots from multiple exchanges.
Design a Pricing Optimization Analytics
Collect competitor price data, inventory levels, demand signals, and run analytics or ML models to set/adjust product prices in near...
Design a Data “Sandbox” Environment
Create a sandbox zone where data scientists spin up ephemeral clusters, run queries or experiments on a subset or masked dataset...
Design a “Usage-based Billing” Analytics System
Collect usage events (API calls, CPU time, requests) from each tenant, store them in near real-time, compute daily or monthly usage...
Design a Synthetic Data Generation & Analytics Platform
Build a system that learns real data distributions, then produces synthetic records that preserve statistical properties but strip or...
Design YouTube
A multi-billion user platform where individuals upload videos, watch personalized recommendations, leave comments, and interact with...
Design Netflix
Users subscribe to watch a library of TV shows/movies with personalized recommendations.
Design Spotify
An on-demand music platform providing streaming or offline playback.
Design Twitch
A live-streaming platform primarily for gaming, featuring near real-time chat overlays, channel subscriptions, donations, plus...
Design Hulu/Disney+
Subscription-based streaming service with on-demand library, plus optional live TV channels.
Design a Video-on-Demand Platform (Generic)
A generic VOD service for internal or external distribution.
Design a Live Concert Streaming Service
A platform streaming live music concerts.
Design SoundCloud
A user-driven platform where creators upload audio tracks, others discover them via tags, waveforms, likes, and can comment at specific...
Design a Podcast Hosting Platform
Creators upload audio episodes, the platform hosts them, automatically generating RSS feeds for Apple/Spotify distribution.
Design an Online Radio Service
Users tune into curated audio streams in real time, with minimal buffering.
Design a DRM-Heavy Media Portal
A platform hosting premium content with robust DRM.
Design a Karaoke Streaming App
Users select songs with synced lyrics on screen, possibly record or share performances.
Design a Multi-Cam Live Sports Streaming
A sports streaming platform offering multiple camera feeds to viewers (e.g., main feed, overhead, bench cam).
Design a Pay-Per-View Event System
A system selling one-time streaming event access.
Design a Movie Ticket Booking & Online Streaming Hybrid
Allows users to book seats for in-theater showings, plus optional online streaming windows for certain movies.
Design an OTT (Over-The-Top) Aggregator
A meta-service letting users connect multiple OTT subscriptions, unify watchlists, track cross-platform progress, and show aggregated...
Design a Music Collaboration Platform
Musicians co-create or exchange audio tracks, record layered sessions, keep version history, do real-time jam sessions or asynchronous...
Design a Screen Recording & Sharing Service
A platform for capturing screen recordings, optionally with camera overlay or voice narration, automatically uploading them for quick...
Design a TikTok-Like Short-Video Editor
A short-form video platform focusing on easy clip creation, editing (filters, transitions, music overlay), plus an endless feed of...
Design a Personalized Music Radio
Generates a continuous station of music for each user based on their tastes or seed tracks.
Design an Audiobook Streaming Service
A platform for audiobook lovers, offering streaming or offline listening.
Design a Lecture Capture & Replay Platform
Captures lectures with screen share or slides, stores them with time-based indexing.
Design an ASMR Content Platform
A niche service for ASMR recordings or streams, focusing on high-quality, binaural audio.
Design a 360-Degree Video Experience
Provide 360° or VR videos with interactive control of viewing angles.
Design a Paywalled Journalism/News Video Hub
A news organization’s video hub, offering free short clips plus locked long-form pieces behind a subscription.
Design a Media Asset Management System
A centralized repository where production teams upload raw media.
Design a White-Label Streaming Service
A streaming backend platform that different clients can rebrand and launch as their “own” service, each with custom branding, domains...
Design a Karaoke Duet Feature
Two remote users each record or perform the same track, possibly in real-time (synchronized singing) or asynchronously.
Design a Watch Party Feature
Users watch the same VOD content in sync.
Design a Recommendation ML Pipeline (Media-Focused)
Collect user watch histories, skip events, rating or likes, and feed them into a specialized model for content-based or collaborative...
Design a Content Classification & Tagging System
System that processes each video or audio, extracts metadata (title, language, content rating).
Design a Video Editing in the Cloud
A web-based editor letting users upload or fetch videos, trim, add transitions, overlay text or music.
Design a Smart Thumbnails Generator
Automatically selects the most engaging frame(s) from a video as a thumbnail.
Design an Audio Fingerprinting Service
When new audio is uploaded or played, the system creates a unique fingerprint to match it against a large database.
Design a Multi-Lingual Subtitle Workflow
A pipeline for generating or ingesting subtitles in multiple languages, syncing them with video timeline.
Design a Gaming Highlights Recorder
Gamers press a button to save a highlight from the last N seconds.
Design a Celebrity Live Interaction Platform
A platform for celebrities to broadcast live, fans can post questions or pay for special shout-outs.
Design a VR/AR Streaming Service
Serve immersive VR or AR experiences over the network, possibly rendering part server-side or offering multi-angle 3D streams.
Design a Secure Screen-Share System
A minimalistic platform focusing purely on secure screen share with end-to-end encryption, ephemeral session links, limited remote...
Design a Clip & Share Feature for Live Streams
While watching a live broadcast (like Twitch), a user can create a 30s highlight clip capturing the last 30s.
Design an Interactive Live Quiz Show (HQ Trivia)
A scheduled quiz show, hundreds or thousands of concurrent players answer multiple-choice questions within a time limit.
Design a Radio Station Automation Platform
A system that schedules tracks, advertisements, announcements in a 24/7 rotation.
Design a Thematic Channel Generator
Algorithmically or editorially create continuous channels (e.g., “Nature Docs,” “Comedy Shorts”).
Design a Personalized Kids-Only Streaming App
A streaming service restricted to children’s shows, with content rated for specific ages.
Design a Paywalled Patreon-Style Content Hub
An online hub letting creators post exclusive videos or audio for paying patrons.
Design a Multi-Stream MUXer
A system that ingests multiple simultaneous streams (e.g., sports camera angles) and merges them into a single feed with optional...
Design a Rolling Buffer for DVR
During a live stream, the system maintains a rolling buffer so users can pause, rewind, or skip forward (back to live).
Design a Real-Time Lyrics Sync Overlay
As a user plays a music video, highlight lyrics in sync with the audio track.
Design a Content ID & Takedown System
When new user-generated video is uploaded, the system checks it against a database of known copyrighted or partner content.
Design a Fair Use / Excerpt Handling System
System that identifies if a user’s uploaded clip is a short excerpt potentially under fair use.
Design Podcast Platform
Host, distribute, and monetize podcasts with analytics.
Design Audio Transcription Service
Convert speech to text with speaker diarization.
Design a Continuous Integration & Deployment (CI/CD) Pipeline
Design a scalable CI/CD platform: fenced control plane, ephemeral runners, trust-scoped remote cache, signed immutable artifacts...
Design Kubernetes for Microservices
Design a multi-team Kubernetes platform: control-plane economics, scheduling, eBPF networking, autoscaling, RBAC tenancy, GitOps...
Design CI/CD Pipeline
Automate build, test, deploy with parallel jobs, artifacts, and rollback capabilities.
Design Kubernetes
Container orchestration with scheduling, auto-scaling, and service discovery.
Design Feature Flag System
Toggle features at runtime with targeting, gradual rollouts, and analytics.
Design Blue-Green Deployment
Zero-downtime deployments with instant rollback and traffic switching.
Design Canary Release System
Gradual rollouts with automated metrics analysis and rollback.
Design Serverless Platform
Function-as-a-service with cold starts, scaling, and event triggers.
Design Infrastructure as Code
Manage resources with declarative configs, state tracking, and drift detection.
Design Container Registry
Store and distribute container images with scanning and access control.
Design Monitoring & Alerting
Collect metrics, define alerts, and visualize system health at scale.
Design Auto-Scaling System
Scale infrastructure based on metrics with predictive and reactive modes.
Design Multi-Region Deployment
Deploy across regions with data replication and failover.
Design Rolling Update Strategy
Update instances gradually while maintaining availability.
Design Log Aggregation
Collect, index, and search logs from distributed systems.
Design Configuration Management
Manage configs across environments with versioning and secrets.
Design Release Orchestration
Coordinate releases across services with approvals and gates.
Design GitOps Workflow
Git as single source of truth with automated sync and drift detection.
Design Build Farm
Distributed builds with caching, parallelization, and artifact management.
Design Database Migration Pipeline
Safe schema changes with backwards compatibility and rollback.
Design DevSecOps Pipeline
Integrate security scans, compliance checks, and vulnerability detection.
Design Chaos Engineering Platform
Test system resilience with controlled failure injection.
Design Ephemeral Environments
On-demand preview environments for every pull request.
Design Immutable Infrastructure
Replace rather than modify servers with versioned images.
Design Service Mesh
Handle service-to-service communication with mTLS and observability.
Design Secrets Management
Store, rotate, and access secrets securely at scale.
Design Cloud Cost Optimization
Track, analyze, and reduce cloud spending automatically.
Design Incident Management
Alert routing, escalation, and on-call scheduling.
Design Artifact Repository
Store and manage build artifacts with versioning and proxying.
Design Deployment Verification
Automated health checks and smoke tests after deployment.
Design Traffic Management
Route traffic with load balancing, rate limiting, and circuit breaking.
Design Backup and Recovery
Automated backups with point-in-time recovery and DR testing.
Design Helm/Operator System
Template Kubernetes deployments with parameterization.
Design Monorepo CI
Efficient CI for large monorepos with affected-only builds.
Design Release Notes Automation
Generate changelogs from commits and PRs automatically.
Design Code Freeze Mechanism
Lock deployments during critical periods with exceptions.
Design SLA Monitoring
Track SLA compliance with alerts and reporting.
Design CI Plugin System
Extensible CI with custom actions and integrations.
Design Environment Promotion
Promote builds through dev, staging, and production.
Design Resource Quotas
Limit resource usage per team or namespace.
Design Pod Scheduling
Optimize container placement with affinity and constraints.
Design Health Check System
Liveness, readiness, and startup probes for services.
Design Log Rotation
Manage log files with rotation, compression, and retention.
Design Certificate Management
Issue, renew, and distribute TLS certificates automatically.
Design Network Policies
Control traffic between services with security rules.
Design Container Security
Scan, sign, and secure container images.
Design Developer Portal
Self-service portal for infrastructure and services.
Design Runbook Automation
Automate operational procedures with triggered playbooks.
Design Deployment Dashboard
Visualize deployment status across services and environments.
Design Dependency Update Automation
Automatically update dependencies with PR creation.
Design Debug Container System
Attach debug containers to running pods for troubleshooting.
Design Capacity Planning
Forecast resource needs based on historical data.
Design an Identity & Access Management System
Design a multi-tenant IAM platform: universal directory, MFA and risk-based step-up, OIDC/SAML SSO, RBAC/ABAC/ReBAC authorization at...
Design a Distributed Logging & Alerting System
Design a durable log ingestion pipeline with tiered search, real-time alert evaluation, event correlation, and notification routing at...
Design Authentication System
OAuth, SSO, MFA with session management and token refresh at scale.
Design Rate Limiter
Distributed rate limiting with multiple algorithms and quotas.
Design API Gateway
Central entry point with auth, rate limiting, and request transformation.
Design Distributed Tracing
Track requests across services with spans and context propagation.
Design Web Application Firewall
Protect against OWASP attacks with rule-based filtering.
Design DDoS Protection
Mitigate volumetric and application-layer attacks at scale.
Design Identity Management
User provisioning, RBAC, and access governance at enterprise scale.
Design SIEM System
Collect, correlate, and analyze security events for threat detection.
Design Encryption Service
Key management, encryption at rest and in transit, with HSM integration.
Design Zero Trust Architecture
Never trust, always verify with continuous authentication.
Design Access Control System
Fine-grained permissions with policies, roles, and inheritance.
Design Audit Logging
Immutable audit trails with tamper detection and compliance.
Design Vulnerability Scanner
Scan infrastructure and code for security vulnerabilities.
Design CAPTCHA System
Distinguish humans from bots with adaptive challenges.
Design Fraud Detection System
ML-based detection of fraudulent transactions and accounts.
Design Password Manager
Secure password storage, generation, and sync across devices.
Design Bot Detection
Identify and block malicious bots with behavioral analysis.
Design Certificate Transparency
Monitor and detect mis-issued TLS certificates.
Design Incident Response Platform
Coordinate security incident investigation and remediation.
Design Threat Intelligence Platform
Aggregate and analyze threat data from multiple sources.
Design Session Management
Secure session handling with timeout, invalidation, and hijacking prevention.
Design API Security
Protect APIs with authentication, authorization, and validation.
Design Data Classification
Automatically classify and tag sensitive data.
Design Data Loss Prevention
Detect and prevent sensitive data exfiltration.
Design Privileged Access Management
Secure and audit privileged account access.
Design Single Sign-On
One login for multiple applications with SAML/OIDC.
Design Key Rotation System
Automated key rotation with zero-downtime migration.
Design Compliance Monitoring
Continuous compliance checks against security standards.
Design Security Dashboard
Unified view of security posture and metrics.
Design APM System
Application performance monitoring with traces and metrics.
Design IP Reputation Service
Score and block malicious IP addresses.
Design Email Security Gateway
Filter spam, phishing, and malware from email.
Design Endpoint Detection
Detect and respond to threats on endpoints.
Design Security Code Scanning
Static and dynamic analysis for vulnerabilities.
Design Network Monitoring
Monitor network traffic for anomalies and threats.
Design Token Management
Issue and validate JWT/OAuth tokens securely.
Design Password Policy Engine
Enforce and validate password requirements.
Design Device Trust
Verify device health and compliance before access.
Design User Behavior Analytics
Detect anomalous user behavior patterns.
Design Firewall Rules Engine
Manage and evaluate network security rules.
Design Security Scoring
Calculate and track organizational security score.
Design Phishing Detection
Identify and block phishing attempts.
Design Security Automation
SOAR platform for automated response workflows.
Design Anomaly Detection
ML-based detection of unusual patterns in data.
Design Secure File Transfer
Encrypted file transfer with audit and compliance.
Design Security Headers Service
Manage and enforce HTTP security headers.
Design Malware Scanning
Scan files and URLs for malicious content.
Design Security Questionnaire
Automate vendor security assessments.
Design Privacy Consent Management
Manage user consent for data processing.
Design Status Page
Public status page with incident communication.
Design Trello (Kanban Board)
Design a real-time collaborative Kanban platform: concurrent ordering with fractional indexing, WebSocket fanout with coalescing...
Design Dropbox
Design a cross-platform file-sync service with content-defined chunking, delta sync, conflict resolution, version history, sharing, and...
Design Google Docs
Real-time collaborative document editing with OT/CRDTs and offline support.
Design Notion
Flexible workspace with blocks, databases, and real-time collaboration.
Design Jira
Issue tracking with workflows, sprints, and customizable fields.
Design Salesforce CRM
Customer relationship management with pipelines and automation.
Design Figma
Collaborative design tool with multiplayer editing and component systems.
Design Confluence
Team wiki and documentation platform with spaces and permissions.
Design Google Calendar
Scheduling with recurring events, invites, and availability.
Design Project Management Tool
Tasks, timelines, dependencies, and resource allocation.
Design Digital Whiteboard
Real-time collaborative whiteboard with drawing and sticky notes.
Design Zapier
Connect apps with automated workflows and triggers.
Design Evernote
Note-taking with rich text, attachments, and powerful search.
Design DocuSign
Electronic signatures with workflows and legal compliance.
Design Desktop Sync Client
Continuous folder sync with conflict resolution.
Design Portfolio Management
Aggregate multiple projects with resource planning.
Design Corporate Intranet
Internal portal with news, search, and employee directory.
Design Expense Management
Receipt capture, approval workflows, and reimbursement.
Design Performance Review Tool
Goals, feedback, and reviews with HR integration.
Design Mind Mapping Tool
Visual brainstorming with collaborative editing.
Design Contract Lifecycle Management
Draft, negotiate, sign, and archive contracts.
Design Org Chart & Directory
Employee hierarchy with search and profiles.
Design White-Label Office Suite
Documents, spreadsheets, and presentations with branding.
Design Unified Chat + Task Platform
Combined messaging, tasks, and calendar for teams.
Design Applicant Tracking System
Candidate pipeline with resume parsing and scheduling.
Design Secure Collaboration Hub
Granular permissions and versioned file sharing.
Design Employee Onboarding
Automated onboarding tasks and form collection.
Design M&A Deal Room
Secure document sharing for legal and financial deals.
Design Resume Builder
Templates, real-time editing, and PDF export.
Design Bug Bounty Platform
Vulnerability submissions with triage and payouts.
Design Virtual Team Building
Online games and activities for remote teams.
Design Presentation Collaboration
Real-time slide editing with presenter view.
Design Cloud IDE
Browser-based coding with containers and collaboration.
Design Training & Certification
Courses, quizzes, and certificate issuance.
Design Survey & Polling Tool
Create surveys with analytics and segmentation.
Design SLA Tracking Dashboard
Track service levels with credits and penalties.
Design ChatOps Platform
Execute commands via chat with bot integrations.
Design Corporate Card System
Virtual cards with budgets and real-time tracking.
Design OKR Tracking Tool
Goals and key results with progress tracking.
Design Print Management
Central queue with authentication and tracking.
Design Internal Q&A Forum
Stack Overflow for teams with knowledge base.
Design Employee Rewards
Points, leaderboards, and reward redemption.
Design Meeting Room Booking
Real-time availability with check-ins and displays.
Design Daily Standup Bot
Automated standup collection and summaries.
Design Approval Workflow Engine
Multi-step approvals with routing and escalation.
Design Form Builder
Drag-and-drop forms with conditional logic.
Design Time Tracking
Track time with projects, reports, and billing.
Design Visitor Management
Check-in visitors with badges and notifications.
Design IT Asset Management
Track hardware and software assets with lifecycle.
Design Help Desk System
Ticket management with SLAs and knowledge base.
Design Employee Feedback
Anonymous feedback with pulse surveys.
Design Uber
Design a global ride-hailing marketplace: H3-based batched matching with fenced offers, real-time location pipelines, dynamic pricing...
Design Lyft
Design Lyft end to end: batched dispatch with offer leases, transparent Prime Time pricing, real-time location and ETA, in-app tipping...
Design DoorDash
Food delivery with restaurant matching, driver dispatch, and real-time tracking.
Design Grab or Gojek (Super App)
Multi-vertical super app with rides, food delivery, payments, and financial services.
Design Google Maps
Navigation with routing, traffic, and real-time updates.
Design Shipment Tracking
Track packages across carriers with real-time updates.
Design Fleet Management
Track and manage vehicle fleets with telematics.
Design Route Optimization
Optimize delivery routes for time and fuel efficiency.
Design Carpooling Platform
Match commuters for shared rides with cost splitting.
Design Last Mile Delivery
Optimize final delivery leg with crowdsourced drivers.
Design EV Charging Network
Find, reserve, and pay for charging stations.
Design Smart Parking System
Find and reserve parking with real-time availability.
Design Bike Sharing System
Dock-based or dockless bike rentals with availability.
Design a Bus Tracking & Route Optimization System
Real-time bus tracking with GTFS, ETA prediction, and route optimization.
Design E-Scooter Platform
Scooter rentals with geofencing and battery management.
Design a Scooter/Bike Sharing Platform
Dockless micromobility with IoT, geofencing, and fleet management.
Design Driver Allocation System
Optimize driver positioning based on demand prediction.
Design Surge Pricing Engine
Dynamic pricing based on supply and demand.
Design Ride Matching Algorithm
Optimal driver-rider matching with constraints.
Design ETA Prediction
Predict arrival times with traffic and ML models.
Design Warehouse Robotics
Coordinate autonomous robots for picking and packing.
Design Truck Load Optimization
Optimize truck routes and loads for freight.
Design Public Transit App
Real-time schedules, delays, and trip planning.
Design Driver Onboarding
Background checks, vehicle validation, and training.
Design Driver Earnings System
Calculate and display earnings with instant pay.
Design Delivery Scheduling
Schedule deliveries with time windows and priorities.
Design Geofencing System
Define and enforce geographic boundaries.
Design Ride Safety Features
Emergency buttons, trip sharing, and driver verification.
Design Driver Rating System
Two-way ratings with quality metrics and deactivation.
Design Food Ordering Flow
Menu browsing, customization, and order placement.
Design Restaurant Dashboard
Order management, menu updates, and analytics.
Design Delivery Batching
Group multiple orders for efficient delivery.
Design Toll Calculation
Calculate and display tolls for routes.
Design Fuel Optimization
Optimize routes and driving behavior for fuel efficiency.
Design Dispatch System
Assign and track jobs for field workers.
Design Smart Locker System
Package delivery to secure lockers with pickup codes.
Design Driver Incentive System
Bonuses, challenges, and gamification for drivers.
Design Proof of Delivery
Capture signatures, photos, and delivery confirmation.
Design Driver Scheduling
Shift scheduling with availability and preferences.
Design Ride Subscription
Monthly passes with discounts and perks.
Design Vehicle Maintenance Tracking
Schedule and track vehicle service and repairs.
Design Driver-Rider Chat
In-app messaging with masked phone numbers.
Design Ride History
Store and display past trips with receipts.
Design Saved Places
Save and manage favorite locations.
Design Fare Splitting
Split ride costs between multiple passengers.
Design Scheduled Rides
Book rides in advance with guaranteed pickup.
Design Airport Queue System
FIFO queue for drivers at airports with rematch.
Design Corporate Travel Program
Business profiles with expense integration.
Design Address Autocomplete
Fast address suggestions with fuzzy matching.
Design Delivery Zone Management
Define and manage service areas with pricing.
Design Driver Document Management
Upload, verify, and track driver documents.
Design Delivery Instructions
Capture and display special delivery notes.
Design Tipping System
In-app tipping with suggested amounts.
Design Order Tracking UI
Real-time order status with map visualization.
Design Flight Search & Booking Engine
Search flights across airlines with caching, booking flow, and price alerts.
Design Hyperlocal Courier Delivery System
On-demand courier dispatch with real-time tracking and SLA management.
Design Train Ticketing & ETA System
Train seat reservation with segment-based inventory and real-time tracking.
Design a Toll Payment & Tracking System
Electronic toll collection with RFID, license plate recognition, and real-time payment processing.
Design a Drone Delivery Network
Autonomous drone delivery with flight path planning, airspace coordination, and fleet management.
Design an EV Charging Station Locator & Booking System
Find and book charging stations with real-time availability and multi-network aggregation.
Design a Corporate Fleet Management System
Vehicle tracking, driver management, ELD compliance, and maintenance scheduling for enterprise fleets.
Design a Cab-Sharing System for Daily Commute
Carpooling platform with route matching, cost splitting, and recurring schedules for commuters.
Design a Long-Distance Bus Ticketing Platform
Bus ticket booking with multi-operator aggregation, seat selection, and dynamic pricing.
Design a Smart Traffic Light Optimization System
Adaptive traffic signals with real-time optimization, corridor coordination, and emergency preemption.
Design an Incident/Accident Alert Network
Real-time traffic incident detection and alerting with multi-source fusion and geospatial targeting.
Design a Shared Autonomous Vehicle (Robotaxi) System
Design a robotaxi fleet: dispatch, ODD eligibility, telemetry ingest, remote-assist, and the safety-first architecture behind autonomous ride-hailing.
Design an EV Battery Swapping Network
Design a battery-swapping network: fungible pack inventory, state-of-health gating, two-sided swap allocation, reservations, and grid-aware charge scheduling.
Design a Cross-Border Ride-Sharing System
Design cross-border ride-sharing: jurisdiction rules engine, distance-split tax, whole-route driver eligibility, multi-currency settlement, and data residency.
Design a Ride-Demand Hotspot Analysis System
Design ride-demand hotspots: streaming H3 aggregation, short-horizon demand forecasting, supply-demand gaps, and convergent driver repositioning guidance.
Design a Drone Traffic Control System (UTM)
Design UTM for drones: 4D deconfliction, strategic plan approval, tactical conflict detection, dynamic geofencing, and federated airspace coordination.
Design a Fleet Vehicle Auction Platform
Design a wholesale car auction: real-time monotonic bidding engine, proxy bids, anti-sniping, condition grading, idempotent settlement, and title transfer.
Design a Real-Time Fuel Price Aggregator
Design a real-time fuel price aggregator: crowd + feed fusion, trust-weighted median scoring, freshness decay, anti-spam, and cheapest-near-me geo queries.
Design a Green Score for Routes
Design eco-routing: a deterministic per-segment emissions model, green-vs-fast scoring, an auditable version-pinned carbon ledger, and eco-scores.
Design an On-Demand Shuttle Service
Design pooled microtransit: dynamic dial-a-ride matching, virtual stops, the insertion heuristic, detour budgets, and batch matching for shared shuttle routing.
Design a Roadside Assistance Dispatch System
Design roadside assistance: capability-matched provider dispatch, offer-accept loop, coverage and claims, severity triage, and spike resilience.
Design a Smart (Keyless) Car Rental System
Design keyless car rental: overlap-free interval booking, offline-verifiable phone-as-key, revocation, telematics damage attribution, and dynamic pricing.
Design a Blockchain-Based Payment System
Design a payment chain with BFT finality, metered smart contracts, tiered custody, off-chain channels and rollups, edge-bound...
Design ChatGPT
Learn to design a ChatGPT-class LLM serving platform: GPU inference, continuous batching, KV cache, token streaming, and scaling to...
Design Voice Assistant
Always-on listening with wake word, NLU, and skills platform.
Design Metaverse Platform
3D virtual world with user presence and item ownership.
Design Autonomous Vehicle System
Self-driving with perception, planning, and control systems.
Design IoT Platform
Connect and manage millions of IoT devices with edge computing.
Design Smart Home Hub
Connect devices with automation rules and voice control.
Design AR Platform
Augmented reality with spatial mapping and object recognition.
Design VR Social Platform
Social VR with avatars, voice, and shared experiences.
Design Drone Delivery System
Autonomous drone deliveries with flight planning and safety.
Design Health Wearable Platform
Track vitals with alerts and health insights.
Design Edge Computing Platform
Deploy compute at the edge with orchestration and sync.
Design Satellite Internet
Global internet via satellite constellation with handoffs.
Design Brain-Computer Interface
Decode neural signals for control and communication.
Design Holographic Conference
Real-time 3D capture and rendering for remote presence.
Design Quantum Computing Service
Cloud access to quantum computers with job scheduling.
Design Robot Fleet Management
Coordinate autonomous robots with task assignment.
Design Digital Twin Platform
Virtual replicas of physical systems with simulation.
Design Smart Energy Grid
Manage distributed energy with demand balancing.
Design Space Mission Telemetry
Collect and process data from spacecraft.
Design Smart Agriculture Platform
Monitor crops with sensors and automate irrigation.
Design 3D Printing Network
Distributed manufacturing with job routing and quality.
Design AR Navigation
Overlay navigation on real-world camera feed.
Design VR Fitness Platform
Gamified workouts with motion tracking and multiplayer.
Design Drone Swarm Coordination
Coordinate multiple drones for shows or mapping.
Design Telehealth Platform
Remote consultations with video and health records.
Design Genomics Data Pipeline
Process and analyze genomic sequencing data.
Design Weather Prediction System
Ingest sensor data and run forecasting models.
Design Satellite Imagery Platform
Capture, process, and analyze earth observation data.
Design AR Virtual Try-On
Try clothes or glasses virtually with AR.
Design 5G Edge Computing
Ultra-low latency compute at 5G network edge.
Design Virtual Event Platform
Online conferences with networking and booths.
Design NFT Marketplace
Mint, buy, and sell digital collectibles.
Design Mobile Mesh Network
Peer-to-peer communication without infrastructure.
Design Smart City Platform
Integrate city services with IoT and analytics.
Design Passwordless Auth
Replace passwords with FIDO2 and biometrics.
Design Robot Service System
Automated service with order queue and coordination.
Design Deepfake Detection
Identify synthetic media with ML analysis.
Design AI Tutoring System
Personalized learning with adaptive curriculum.
Design Voice Cloning Platform
Clone voices with consent for personalized TTS.
Design Virtual Museum
3D exhibits with interactive tours.
Design Haptic Feedback System
Tactile feedback for VR and remote interaction.
Design Smart Mirror
Display information overlay on mirrors.
Design Gesture Control System
Control devices with hand gestures.
Design Sleep Tracking Platform
Monitor sleep patterns with insights and coaching.
Design Carbon Footprint Tracker
Calculate and offset carbon emissions.
Design Smart Glasses Platform
Lightweight AR glasses with notifications and camera.
Design Emotion Detection
Analyze facial expressions and voice for emotions.
Design Contact Tracing
Privacy-preserving exposure notification.
Design Autonomous Ship System
Self-navigating vessels with collision avoidance.
Design Vertical Farming System
Automated indoor farming with environment control.
Design a Permissionless Public Blockchain
Build a public blockchain network where anyone can participate in block creation, with no gatekeeping.
Design a Permissioned Enterprise Blockchain (Hyperledger-like)
A private/consortium ledger for a group of trusted participants (e.g., banks or supply chain partners).
Design a Cross-Chain Bridge
A protocol that locks assets on one chain (e.g., Ethereum) and issues corresponding wrapped tokens on another chain (e.g., Polygon)...
Design a Central Bank Digital Currency (CBDC)
A state-issued digital currency system run on a controlled ledger.
Design a Crypto Exchange (Centralized)
A centralized crypto exchange platform that lists various coins, allowing limit or market orders in real-time.
Design a Crypto Wallet (Self-Custodial)
A self-custodial wallet that allows users full control of their private keys (mnemonic seed phrase).
Design a DeFi Lending & Borrowing Protocol
A decentralized protocol where users deposit assets to earn interest, while others borrow against posted collateral.
Design a Layer-2 Rollup for Ethereum
A layer-2 network on top of Ethereum that processes many transactions off-chain, then posts succinct proofs or batched data to L1.
Design a Blockchain Oracle Network
A decentralized oracle solution that fetches external data (like asset prices, sports results, or weather info) and delivers them...
Design a Zero-Knowledge Identity Verification System
A system letting users prove certain attributes (e.g., “I am over 18,” “I belong to country X”) without disclosing the underlying data.
Design a Token Launchpad (IDO/ICO Platform)
A launchpad for new token sales (IDOs or ICOs).
Design a Crypto Payment Gateway for E-Commerce
A payment gateway letting e-commerce merchants accept Bitcoin, Ethereum, or stablecoins at checkout, optionally auto-converting to fiat.
Design a Crypto Payment Channel Network (Like Lightning)
A second-layer network allowing users to open payment channels by locking funds on-chain, then exchange many micropayments off-chain.
Design a Crypto Derivatives DEX (Futures/Options)
A decentralized exchange for trading futures or options on crypto assets.
Design a DAO Governance Platform
A governance system letting token holders propose new protocol changes or spending, discuss them on a governance forum, and vote using...
Design a Crypto Mining Pool
A mining pool server that aggregates hashing power from many miners, distributing partial work (shares) with adjustable difficulty...
Design a Multi-Chain Token Management Dashboard
A unified UI that queries multiple blockchains or bridging solutions to display a user’s token holdings in one place.
Design a Multi-Sig Vault Protocol
A protocol letting multiple signers collectively manage a wallet.
Design a Crypto Treasury Management System
An internal system that manages an organization’s crypto treasury across multiple wallets or exchanges.
Design a Privacy Coin Using Zero-Knowledge
A blockchain protocol that hides transaction amounts and addresses using zero-knowledge proofs.
Design a On-Chain Reputation System
A protocol awarding reputation tokens or badges to addresses that meet certain criteria (e.g., consistent on-time repayment, or active...
Design a Semi-Fungible Token System (ERC-1155)
A token contract that can handle multiple token types under one standard (like ERC-1155).
Design a Crypto Market-Making Bot (AMM or Order Book)
A market-making bot that continuously places buy/sell orders on a CEX order book or AMM pool, balancing an inventory of tokens.
Design a Supply Chain Tracking DApp
A decentralized app where each participant in the supply chain (manufacturer, shipper, retailer) logs product movement on a permissioned...
Design a Crypto Lending Circle or ROSCA
A decentralized version of rotating savings (like a “sou-sou” or “tanda”), where participants deposit a fixed amount each cycle, and...
Design a Crypto Identity-Linked Airdrop
A system awarding free tokens to unique participants meeting certain criteria, but must avoid mass exploitation by fake addresses.
Design a Carbon Credit Trading on Blockchain
A platform turning verified carbon credits into tokens, each representing 1 ton CO2 offset.
Design a Token Curated Registry (TCR)
A system where a list (e.g., “trusted crypto projects” or “top restaurants”) is curated by token holders.
Design a Gaming DAO with On-Chain Items
A gaming ecosystem where a DAO of token-holding players collectively decides game rules, expansions, or item balancing.
Design a Blockchain Sharding Protocol
A design that partitions the blockchain state into multiple shards, each processing subsets of transactions in parallel.
Design a Crypto Reward System for Physical Activity
A system awarding crypto tokens to users who prove they performed physical activities (steps, distance).
Design a Proof-of-Location Blockchain
A specialized blockchain network where participants prove their real-world location via trusted hardware or multi-party witness checks.
Design a Crypto Tipping Platform for Social Media
A system allowing easy tipping (micropayments) on major social networks (Twitter, Reddit), using browser extensions or integrated APIs.
Design a Blockchain E-Voting System
A system for secure and anonymous elections, where each registered voter can cast exactly one ballot on-chain.
Design a Crypto Escrow Service
A platform that locks crypto funds in a smart contract until buyer and seller confirm successful transaction (like an eBay sale, or...
Design a Gasless Meta-Transaction System
A system letting dApp users sign messages that a relayer then wraps into on-chain transactions, paying gas.
Design a Crypto Social Feed with Token Rewards (Steemit-like)
A decentralized blogging or microblogging site where content upvotes or comments mint tokens for the creator, aligning user engagement...
Design a Blockchain DNS Alternative (Name Service)
A system that replaces hex addresses with user-friendly names (e.g., alice.crypto), stored on-chain.
Design a Crypto E-Voting for DAOs with Quadratic Voting
A governance system using quadratic voting: each token holder can allocate votes to proposals, but the cost of each additional vote...
Design a Crypto ATM Network
A network of physical ATMs that let users insert cash to buy BTC or other tokens, or withdraw cash by selling crypto.
Design an NFT Raffle/Lottery Platform
A platform issuing NFT-based raffle tickets, each a unique token.
Design a Blockchain Domain Squatting Resolver
An arbitration layer or mechanism integrated with a blockchain name service.
Design a Layer-1 PoS Blockchain with Governance
A brand-new blockchain that uses delegated or pure proof-of-stake for block production.
Design a P2P Fiat-Crypto Escrow Marketplace
A marketplace where individuals post buy/sell offers for crypto in exchange for local fiat, set price rates, and meet offline or use...
Design an Algorithmic Stablecoin
A stablecoin protocol that tries to hold $1 peg not via fiat reserves but through on-chain algorithms: if price < 1, buy back tokens or...
Design a Crypto Micro-Task Platform (Gig economy)
A decentralized platform where requesters post tasks (like image labeling, short translations), workers fulfill them, and get paid tiny...
Design a Crypto Payment Splitter Contract
A smart contract receiving inbound payments (like from a DeFi protocol, NFT royalties, or revenue share) and automatically splitting...
Design a Crypto Custodial Solution (Bank-Style)
A regulated custodian platform where corporate or institutional clients deposit large amounts of crypto.
Design a Blockchain-Backed Real Estate Registry
A system that puts real estate property deeds or partial ownership shares on a blockchain.
Design a Blockchain Auction for Real-World Assets
A platform that auctions physical assets, yet the bidding and final payment happen via on-chain tokens.
Design a Large-Scale Model Training Pipeline (Foundation Model)
A pipeline to train massive language or multimodal models (billions of parameters) from diverse data.
Design an AI Agent Orchestration Framework
A system that orchestrates one or more AI agents, each capable of dynamic reasoning, calling external APIs or tools, and maintaining...
Design a Real-Time Recommendation System (Stream-based)
A pipeline that ingests user clickstream or watch data continuously, updates a recommendation model or session-based approach (like...
Design a Chatbot for Customer Support with LLM & Knowledge Base
A support chatbot that uses an LLM for natural conversation, but references an up-to-date knowledge base.
Design a Real-Time Voice Assistant (Speech + LLM)
A system that listens to user speech (real-time streaming), transcribes it, uses an LLM to interpret or answer queries, then responds...
Design a Self-Driving Car Perception & Planning Stack
A pipeline that ingests sensor data (camera, LiDAR, radar) for object detection, merges them into a scene understanding, predicts...
Design a ML-Driven Content Moderation System (Text/Image/Video)
A pipeline that takes user-generated content (text, images, or videos), runs ML models to detect hate speech, nudity, violence, or...
Design a Federated Learning Platform
A platform enabling training across many edge devices or client apps.
Design an AutoML Service for Non-Technical Users
A platform where users upload datasets (CSV or database link), select a target column for prediction, and the system automatically tries...
Design a GPT-Based Code Generation & Testing Service
A service that takes user prompts describing desired code functionality, uses a GPT-based model to generate code stubs or entire...
Design a Reinforcement Learning for Industrial Robotics
An RL system that trains an industrial robot to pick items from a conveyor belt or assemble parts.
Design a Hybrid Recommender (Content-based + Collaborative)
A recommender system merging collaborative filtering embeddings from user-item interactions with content-based embeddings (item genres...
Design a ML Model Deployment & A/B Testing Platform
A platform that takes newly trained models, containerizes them for inference, deploys them to a fraction of traffic (canary or...
Design a Multi-Agent Simulation for Finance Trading
A simulator that spawns many trading agents, each with distinct strategies (market making, momentum, etc.), interacting in an order book...
Design an AI Programmatic Ad-Bidding System (RTB)
A real-time bidder that receives ad impressions from an exchange, runs a CTR or ROI prediction model, decides the bid price within tens...
Design a Large-Scale Vector Database for Embeddings
A specialized DB for storing high-dimensional embeddings (like 512D or 1024D vectors from an LLM or image model).
Design an Edge ML Inference Platform (Mobile/IoT)
A platform that deploys compressed or quantized ML models to edge devices (phones, embedded boards) for low-latency inference.
Design a Transfer Learning Hub (Foundation to Fine-Tuning)
A service that hosts multiple pretrained large models (like BERT or GPT variants) and automates fine-tuning them on user-provided domain...
Design an MLOps Pipeline for Continual Learning
A system that ingests new data or user feedback daily/weekly, updates an existing model incrementally (e.g., replay buffer or domain...
Design a Knowledge Graph Construction from Text (NLP)
A pipeline that reads large corpora of text (news, docs), uses NLP to identify entities (people, organizations, places) and the...
Design a Hyper-Personalized News Feed using LLM Summaries
A personalized news aggregator that scrapes articles, uses an LLM to summarize each snippet, and ranks them by user preference profiles.
Design a Speech Emotion Recognition System
A pipeline that takes audio streams or recorded calls, runs a model to classify emotional states (happy, sad, angry, neutral, etc.)...
Design an AI Content Generation Pipeline for Marketing
A generative AI pipeline to produce marketing copy or social media posts in the brand’s tone.
Design a Generative Image/Video Service (Stable Diffusion style)
A service that takes textual prompts or partial images, runs a diffusion-based generative model to produce new images or short video clips.
Design a Synthetic Data Generation Pipeline (Privacy)
A system that ingests real user data, trains generative models to produce synthetic samples that mirror statistical distributions...
Design a Multi-Lingual Machine Translation Service
A translation API that handles text or documents in dozens of languages.
Design a Time-Series Forecasting Pipeline (Retail Demand)
A system that aggregates historical sales or demand data for numerous products, runs a forecasting model (Prophet, LSTM, Transformers...
Design a Vision Transformer for Medical Image Diagnosis
A pipeline that trains or fine-tunes a vision transformer on labeled medical images (chest X-rays, MRI slices) to diagnose conditions.
Design a Reinforcement Learning Recommender (Bandit approach)
A recommender that treats each user impression as a bandit trial, picks an item to show, observes immediate reward (click or not), and...
Design a Data Labeling Platform with Active Learning
A platform where human labelers tag images/text.
Design an Explainable AI Dashboard
A web-based dashboard that shows predictions from an ML model, plus explanation of features that influenced the result (e.g., SHAP, LIME).
Design a Continual Visual Recognition for Retail Shelves
A system that reads camera feeds pointed at store shelves, runs object detection or classification to see if items are missing...
Design a Federated ChatGPT for Enterprise Privacy
A solution for large enterprises wanting ChatGPT-like capabilities but ensuring local data remains on-site or behind a firewall.
Design a Drone Swarm for Crop Spraying with RL
A multi-agent RL system controlling a fleet of drones that apply pesticide or fertilizer on farmland.
Design an RPA System with Vision + LLM for Agents
A system for automating business processes that includes screen scraping or element detection, plus an LLM that can interpret error...
Design a Gesture Recognition & Control System (AR/VR)
A system that uses a camera or depth sensor to detect user hand gestures or full-body motions, interprets them as input commands (like...
Design a Workflow of LLM Agents for Data Analysis
A system that automates data analysis using a chain of LLM-based “agents”: first agent cleans data and sets columns, second agent runs...
Design a Video Analytics System for Traffic Monitoring with ML
A platform ingesting live video from city traffic cameras, runs object detection or vehicle counting, calculates speed or congestion...
Design a Robot Chat Companion with Personality AI
A robot or avatar that chats with users, using an LLM but locked into a certain personality or backstory, e.g., a helpful medieval...
Design a Federated Vision Analytics for Hospitals (HIPAA compliance)
A system that trains a model for detecting pathologies in scans across multiple hospitals, but each hospital never shares raw images.
Design an Interactive Story-Generation AI (Multi-User)
A web app letting a small group of users write a story collectively.
Design a Microservice for Model Explanation as a Service (XaaS)
A microservice that, when given a model reference plus input instance, runs an interpretability technique (SHAP, LIME, or integrated...
Design a Synthetic Voice Cloning Service (TTS)
A platform that, given a user’s voice samples, trains or fine-tunes a TTS model to produce that voice.
Design a UAV Swarm for Wildlife Tracking & ML Classification
A set of UAVs that systematically fly over wildlife reserves, capturing images or videos.
Design a Document QA System with Hybrid Retrieval (Keyword + Vector)
A question-answering pipeline that first does keyword or BM25-based retrieval for potential relevant docs, then uses a vector search or...
Design an Auto-Response System for Emails (Smart Reply)
A service that scans incoming emails, proposes 2–3 short reply suggestions (like “Sure, let’s do that!”).
Design a Multi-Task Learning System (Unified Model)
A single neural network that can handle multiple tasks from different domains (e.g., text classification, sentiment, NER, or even...
Design a Self-Learning Bot for E-Commerce Chat (User Feedback Loop)
An e-commerce chat assistant that guides users to relevant products or solves queries.
Design a On-Device Continual Learning for Keyboard Suggestions
A mobile keyboard app that learns the user’s typing patterns, new slang or domain words locally, adjusting predictions over time.
Design a ChatGPT Plugin for Live Code Testing & Execution
A plugin letting ChatGPT users write code snippets, then execute them in a sandbox environment.