"Whiteboard.ai" — Collaborative System-Design Whiteboard

A real-time collaborative whiteboard for system design where an AI reviews your architecture diagram like a senior engineer — for interview practice, live interviews and team design reviews. Boards are Yjs documents synced over a custom WebSocket server, persisted to Postgres within ~50 ms and editable offline. The canvas is converted into a typed graph that a deterministic rules engine checks before Claude writes a structured review with findings pinned to shapes. Includes email/OAuth sign-in, role-based sharing with an audit log, end-to-end encrypted private rooms, multi-instance sync over Redis, Row Level Security on every table, and a CI pipeline with load tests and secret scanning.