Node.js WebSockets in Production: Socket.io, ws, and Scaling to Multiple Nodes

Node.js WebSockets in Production: Socket.io, ws, and Scaling to Multiple Nodes WebSockets are deceptively simple to get working locally and surprisingly difficult to operate correctly in production. A single Node.js process handles connections fine. Add a load balancer and a second process, and you discover that half your clients are silently broken. Add a rolling deployment, and you discover that connections drop without warning. Add authentication, and you discover that the WebSocket handshake is a one-shot window you can't retry. This guide covers what you actually need to deploy WebSocket servers correctly at scale. ws vs Socket.io: Choose the Right Abstraction Before choosing a library, understand what each one buys you. ws is a minimal WebSocket implementation. It speaks the protocol and nothing else — no rooms, no reconnection, no fallbacks. Use it when you own the client stack, want minimal overhead, or are building a binary protocol on top of WebSockets (game servers, trading