Building WebSocket Server Overview Build scalable WebSocket servers for real-time bidirectional communication using the library, Socket.IO, or native framework WebSocket support. Handle connection lifecycle management, room/channel subscriptions, message broadcasting, heartbeat keepalive, and horizontal scaling with Redis pub/sub adapters. Prerequisites - Node.js 18+ with or , or Python 3.10+ with or FastAPI WebSocket, or Go with - Redis for horizontal scaling with pub/sub adapter (Socket.IO Redis adapter, or manual pub/sub) - Load balancer configured for WebSocket upgrade (sticky sessions or…