Live stream chat is deceptively hard. What starts as "just broadcast messages to connected clients" becomes a distributed systems problem the moment you scale past a single server instance.

Wapi is a live streaming app tailored for African content, with a backend written in Go. Its chat takes a pragmatic approach to scaling: an in-memory WebSocket hub per process, with an optional Redis Pub/Sub broadcaster for cross-instance fan-out. In this post I'll break down why the design works, what it costs you, and where it starts to strain.

The Problem With Single-Instance Chat

If you only ever run one backend instance, keeping all connected clients in memory and broadcasting to them directly is the simplest and fastest option. You get low latency, no external dependencies, and a system that is easy to reason about.…