Design a booking system

Design an online booking system (e.g., for hotel rooms, meeting rooms, or appointment slots).

Requirements

Cover the following in your design:

• Core flows : search availability, create booking (reserve), confirm, cancel, modify.
• Correctness : prevent double-booking under high concurrency.
• Scale : support many users and a large inventory (properties/rooms/slots).
• Latency : fast availability queries.
• Reliability : handle retries, partial failures, idempotency.

Clarifications to address

• What consistency guarantees are needed for availability and booking creation?
• Do you need a “hold” (temporary reservation) with expiration?
• How do you model inventory (per day, per time slot, per resource)?

Provide APIs, data model, and a high-level architecture, and discuss tradeoffs.