Realtime & Streaming
Pushing data to a client that is already connected — and the connection state that makes it the hardest thing to scale.
5 topics
Choosing a Realtime Transport
Polling, SSE and WebSockets compared on the axes that actually decide it — direction, infrastructure tolerance, and reconnection.
core20 minServer-Sent Events from a Service
The wire format, the headers that stop proxies buffering you, and the resumability you get by emitting event IDs.
core20 minWebSockets in Production
Everything HTTP was doing for you that you now have to write — auth, heartbeats, reconnection with state recovery, and per-connection limits.
core25 minProxying an LLM Stream
The backend every AI product has — relaying provider tokens to the browser while keeping the key, the abort, the cost, and the transcript.
core25 minScaling Connections & Fanout
Why stateful connections break horizontal scaling, and the three ways a message reaches a client attached to a different instance.
deep25 min