#websockets

build real-time collaboration

Add a real-time collaborative layer to an app: live cursors plus click-to-drop comment pins, like Figma. Use WebSocket (Socket.io or native ws). Requirements: other users' cursors shown live, comments appear for everyone instantly, graceful reconnect with no ghost cursors, debounced cursor updates. Build it end to end, then prove sync works with two simulated clients before calling it done.