Decisions and Assumptions

Decisions

Topic	Decision	Why
Backend	Java 21, Spring Boot 4	Mature transaction, locking, and WebSocket support
Frontend	React + TypeScript + Vite	Fine-grained rendering control for a live grid
Database	PostgreSQL via Docker Compose	Real row locking (SELECT ... FOR UPDATE) and constraints, which the race fix depends on
Integration tests	Testcontainers PostgreSQL, not H2	H2's locking differs from Postgres, so race tests against it prove little
Booking period	Whole day	Simplest conflict model; one booking per desk per day
Bookings per employee	At most one per day	Enforced by a unique constraint
Neighbours	Configurable per floor: ORTHOGONAL (default) or ALL	Different floors can need different spacing
Sign-in	Username and password → JWT, with seeded demo users	Per-user security without an external identity provider
Live updates	STOMP over WebSocket, per-desk updates with a version	Small messages, ordered per desk, easy to resync

Assumptions

These were assumed to keep the scope clear. Change them here and in the repo CLAUDE.md if they turn out to be wrong.

• Date means the office's local date, set as a single time zone in configuration.
• Booking window: from today up to 14 days ahead. Past dates are rejected.
• Floors are created only through seed data. There's no admin screen for editing floors.
• Cancelling a booking deletes it. Users can cancel only their own bookings.