Requirements and Constraints

Puzzle games prioritize correctness and idempotency over sub-millisecond latency.

Wordle, chess, and crosswords share a pattern: low write QPS, strict correctness, and leaderboard reads that must not scan every player row at request time.

Wordle at scale

One puzzle ID per day with server-side answer validation. A second submit from the same account must return the original result, not a duplicate score.

Correctness over speed

An illegal move rejected in 50 ms beats a wrong move accepted in 5 ms. Budget infra for validation and idempotency, not UDP fleets.

Key Takeaways

Server validates every move against game rules — client hints are not authoritative.
Daily puzzles: one submission per user per calendar day (idempotent).
Async play: opponents may move hours apart; push on turn notification.
Timers and forfeits need durable scheduled jobs, not in-memory only.
Leaderboards need fast top-K reads at millions of players.
HTTPS suffices — payloads are small; UDP is unnecessary.

requirementsvalidationidempotencydaily puzzleleaderboard

Back-of-the-Envelope Estimation →