Lumodraw
Built a real-time collaborative whiteboard using Next.js, WebSockets, Socket.IO, Node.js, Express.js, and PostgreSQL, supporting 50+ concurrent users per room with sub-100ms synchronization latency. Developed a 60fps HTML5 Canvas rendering engine, multi-element grouping, infinite workspace zoom and pan, Command Pattern-based undo/redo, room-based collaboration, shareable session links, auto-save, and PNG, SVG, and JSON export/import.