Orihime Tablekeeper

Orhime Tablekeeper is a modern restaurant reservation system designed to provide a secure, reliable, and conflict-free table booking experience. The core problem it solves is double booking, where multiple customers attempt to reserve the same table for overlapping time slots. The platform allows users to select a restaurant, specify the number of guests, choose a preferred date and time, verify their identity through OTP authentication, and confirm their reservation. Each successful booking receives a unique confirmation code, while users can also manage and cancel their reservations. The key strength of Tablekeeper is its concurrency-safe booking architecture. Instead of relying only on frontend availability checks, the system uses PostgreSQL transactions, row-level locking, and database-level exclusion constraints to ensure that conflicting reservations cannot be created. Even when multiple users attempt to book the same table simultaneously, the database guarantees that only a valid reservation is accepted. The system also incorporates idempotency protection to prevent duplicate bookings from repeated requests, along with rate limiting for booking and verification operations. Time-range validation and proper transaction handling further improve reliability. Tablekeeper demonstrates how a reservation platform can combine a simple user experience with robust backend engineering. Its architecture focuses on data consistency, security, concurrency control, and reliability, making it suitable for real-world restaurant booking scenarios where simultaneous users and race conditions are common. The project's main principle is simple: one table, one time slot, one valid reservation — even under heavy concurrent demand.