Scaling WebSocket Connections: From Single Server to Distributed Architecture

Both Write and Bash are denied. Since you asked me to output the article, here it is directly: Most tutorials stop at "here's how to set up a WebSocket server." Then you deploy to production, traffic grows, and you realize a single Node.js process can't hold 50,000 concurrent connections without melting. This article walks through the real engineering decisions behind scaling WebSocket connections — from a single server prototype to a distributed architecture that handles hundreds of thousands of simultaneous users. This is part of the **Production Backend Patterns* series, where we tackle infrastructure problems you'll actually face in production.* Starting Point: A Single-Server WebSocket Setup Let's begin with the baseline. A straightforward WebSocket server using the ws library in Node.js: import { WebSocketServer, WebSocket } from "ws"; import { createServer } from "http"; interface Client { id: string; ws: WebSocket; rooms: Set<string>; lastPing: number; } const server = cr