Design On-Chain Voting - System Design | WinJob

Problem Statement: On-Chain Governance Voting at DAO Scale

Design a Snapshot / Tally / Compound-class on-chain governance voting platform where token holders propose protocol changes, cast weighted or quadratic ballots, and execute passed actions through a timelock. This section focuses on problem during the understanding phase.

Mechanism

Compound-style Governor with checkpointed ERC20Votes weights at snapshot block
Snapshot hub ingests EIP-712 ballots; relayer posts results on-chain when strategy demands binding execution
Tally-style indexer replays VoteCast and ProposalCreated for sub-second UI tallies
Optional quadratic credits cap whale dominance while preserving one-person-one-vote intent

Quantified anchors

42M governance tokens outstanding; 6.5% supply typically delegates
7-day voting period; 400k VoteCast events/day peak during contentious upgrades
Quadratic mode: 100 credit budget/voter/season; cost(n votes)=n² on a single proposal

Component focus (TokenHolder, ProposalHub, VoteEngine, Timelock)

Trace how TokenHolder hands off to ProposalHub under load
VoteEngine projections must be idempotent across reorgs
Timelock is the execution or observability boundary

Governance invariants

Vote weight at snapshot block is authoritative; off-chain tallies are hints until relayed
Relayers cannot exceed on-chain quorum when posting Snapshot results
Simulation precedes queue; timelock ETA is user-visible

Failure drills

Flash-loan acquisition in creation block blocked by votingDelay
IPFS gateway slow: show hash on-chain, degrade rationale UI only
Quadratic Sybil: reject duplicate identity wallets

Interview checkpoints

Quote concrete numbers (quorum 4%, threshold 100k tokens, 48h timelock)
Separate signaling vs binding paths in one sentence
Name Snapshot, Tally, Compound parallels when asked

Depth note 1.1: Compound-style Governor with checkpointed ERC20Votes weights at snapshot block — impacts vote latency, relayer budget, and tally correctness for problem.

Depth note 1.2: Snapshot hub ingests EIP-712 ballots; relayer posts results on-chain when strategy demands binding execution — impacts vote latency, relayer budget, and tally correctness for problem.

Depth note 1.3: Tally-style indexer replays VoteCast and ProposalCreated for sub-second UI tallies — impacts vote latency, relayer budget, and tally correctness for problem.

Depth note 1.4: Optional quadratic credits cap whale dominance while preserving one-person-one-vote intent — impacts vote latency, relayer budget, and tally correctness for problem.

Depth note 1.5: Compound-style Governor with checkpointed ERC20Votes weights at snapshot block — impacts vote latency, relayer budget, and tally correctness for problem.

Depth note 1.6: Snapshot hub ingests EIP-712 ballots; relayer posts results on-chain when strategy demands binding execution — impacts vote latency, relayer budget, and tally correctness for problem.

javaOne Dark Pro

1 public final class GovVote1 {
2   public static final String TOPIC = "problem";
3   public boolean quorumMet(long forVotes, long against, long supply, int quorumBps) {
4     return (forVotes + against) * 10_000L >= supply * quorumBps;
5   }
6 }

pythonOne Dark Pro

1 SECTION_1_TOPIC = "problem"
2 TOKEN_SUPPLY = 42_000_000
3  
4 def quadratic_cost(vote_units: int) -> int:
5     return vote_units * vote_units

typescriptOne Dark Pro

1 export const SECTION_1 = { topic: 'problem', phase: 'understanding' };
2 export function quadraticCost(units: number): number {
3   return units * units;
4 }

Why interviewers care

On-Chain Voting interviews reward crisp scope, explicit trade-offs, and failure stories—not generic microservice diagrams.

Interview checkpoint

Name one failure story for Problem Statement: On-Chain Governance Voting at DAO Scale that proves you understand real outages, not happy-path diagrams.

Key Highlights

•Compound-style Governor with checkpointed ERC20Votes weights at snapshot block
•Snapshot hub ingests EIP-712 ballots; relayer posts results on-chain when strategy demands binding execution.
•Tally-style indexer replays VoteCast and ProposalCreated for sub-second UI tallies
•Optional quadratic credits cap whale dominance while preserving one-person-one-vote intent

1	public final class GovVote1 {
2	public static final String TOPIC = "problem";
3	public boolean quorumMet(long forVotes, long against, long supply, int quorumBps) {
4	return (forVotes + against) * 10_000L >= supply * quorumBps;
5	}
6	}

1	SECTION_1_TOPIC = "problem"
2	TOKEN_SUPPLY = 42_000_000
3
4	def quadratic_cost(vote_units: int) -> int:
5	return vote_units * vote_units

1	export const SECTION_1 = { topic: 'problem', phase: 'understanding' };
2	export function quadraticCost(units: number): number {
3	return units * units;
4	}