I jumped straight into the database schema and seat reservation logic, which felt right at the time, but I think I skipped over clarifying questions that would've helped a lot.
Start by clarifying functional and non-functional requirements, such as expected scale, consistency needs, and peak traffic patterns. Then design a high-level architecture that separates concerns: seat inventory, order processing, payment, and notification. Finally, dive into critical components like concurrency control for seat locking and database sharding for scalability.
Pro tip: Emphasize the trade-offs between strong consistency and availability during peak sales, and propose a hybrid approach like using a distributed lock service (e.g., Chubby) for seat reservation while allowing eventual consistency for less critical data.
Ask about scale (e.g., millions of users, thousands of concerts), consistency requirements (e.g., no double-booking), and latency expectations. Also clarify read vs. write patterns and peak load scenarios.
Outline core services: event catalog, seat inventory, order service, payment, and notification. Sketch how they interact via APIs and message queues.
Design schemas for events, venues, seats, and orders. Choose databases: e.g., relational for transactions, NoSQL for catalog, and caching for hot data.
Address seat locking to prevent double-booking. Discuss optimistic vs. pessimistic locking, distributed locks, and idempotency for payment.
Explain sharding by event or venue, read replicas, caching strategies, and handling failures with retries and circuit breakers.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.