Documentation
How WinJob is organised, what each course covers, and how access, AI evaluation and credits work.
WinJob is interview preparation for senior engineering roles. It is four courses that share one account, one library format and one progress model.
This documentation covers how the product is organised and how the parts that are easy to get wrong — access tiers, free content, AI evaluation and credits — actually behave.
The four courses
| Course | Covers | Where it lives |
|---|---|---|
| WinSystemDesign | Distributed-system design interviews: 634 authored questions across 12 domains, plus concepts, diagrams and pattern libraries | /app/win-system-design |
| WinAI | AI and ML interviews: 202 questions, 401 quizzes, 613 flash cards, prompt packs and structured tracks | /app/win-ai-mastery |
| WinCloud | Cloud architecture: 1,000 interview questions, diagrams and workflow patterns | /app/win-cloud |
| WinOps | Running production: incident playbooks, runbooks, on-call guides and compliance checklists | /app/win-ops |
Each course is browsed the same way, so what you learn about navigating one applies to all four.
How a course is organised
Every course exposes the same content types. Not every course has every type populated yet, and a type with no content is not linked in that course's sidebar.
- Questions — the long-form pieces. A question page is a full walkthrough: requirements, estimates, the design, trade-offs and follow-ups.
- Concepts — the building blocks a question assumes you already know.
- Quizzes — timed multiple-choice sets, scored and repeatable.
- Flash cards — spaced recall over the same material.
- Diagrams — architecture diagrams you can open full-screen and pan.
- Cheat codes, quick tips, pitfalls, follow-up questions — short reference material, meant to be skimmed the day before an interview.
- Workflow patterns and architecture patterns — reusable shapes that recur across many questions.
Most of these have a full-screen twin: the same library without the course
chrome, at /app/concepts, /app/diagrams, /app/cheat-codes and so on.
The full-screen route is the same content under the same access rules.
Access
Access is decided on the server, not in the browser. Five tiers exist:
| Tier | Courses | AI | Monthly credits |
|---|---|---|---|
| Free | A sample of every course | No | 0 |
| Pro | WinSystemDesign | No | 0 |
| AI | WinSystemDesign | Yes | 10,000 |
| Bundle | All four | Yes | 10,000 |
| Interview Sprint | All four, plus the sprint workspace | Yes | 25,000 |
Free is not a trial that expires. It is a permanent allow-list: a fixed set of items in each category stays open on every course, so you can read a complete question end to end before deciding whether to buy.
Anything outside that allow-list shows a locked page with the tier that would unlock it. If you hold a plan and still see a locked page, that is a bug, not a grace period — the same check runs on the server and on the page, and they read the same catalogue.
AI features and credits
AI features — the evaluator, the predictor, the promotion planner and AI chat — require a tier with the AI capability. That is the AI tier or the Bundle; Pro deliberately does not include them.
AI work spends credits from a monthly wallet. Credits refill with the billing
period and do not roll over. Every spend is written to a ledger you can read at
/app/credits, so a balance is always explainable rather than merely asserted.
If a plan grants AI but a feature still refuses, the cause is almost always an empty wallet rather than a missing entitlement, and the page says which.
Interview Research
Interview Research is the company intelligence sibling of Interview Sprint: citation-backed engineering DNA, trail, and prep translation — never predicted interview questions from blog topics. Access and the 1000-credit run cost are documented there.
Where to go next
Start with Getting started for a walkthrough of your first session, then Plans and access if you want the exact rules behind what is locked and why.