WebSockets give you a persistent, bidirectional connection between client and server — the foundation for chat, live collaboration, dashboards, and multiplayer features. The protocol is the easy part; the hard parts are the patterns around it: choosing WebSockets over simpler options, handling the messy reality of connections dropping, scaling stateful connections across servers, and authenticating them. Those patterns are where real-time apps succeed or struggle.
WebSockets, SSE, or polling
| Need | Use |
|---|---|
| Bidirectional, low-latency (chat, collaboration) | WebSockets |
| Server-to-client stream only (live feed, notifications) | Server-Sent Events (SSE) |
| Infrequent updates, simplicity | Polling |
Do not default to WebSockets. If you only need the server to push to the client — a notification stream, a live feed — Server-Sent Events are simpler, run over plain HTTP, and reconnect automatically. Reserve WebSockets for genuine bidirectional, low-latency needs. Choosing the simplest option that meets the need saves you the operational weight of the more complex one.
Connection lifecycle and reconnection
Connections drop — networks change, laptops sleep, servers restart — so robust reconnection is non-negotiable, not an edge case. Implement reconnection with exponential backoff (and jitter) so a server blip does not trigger a reconnect storm from every client at once. On reconnect, re-establish subscriptions and resynchronise any state missed while disconnected, because a reconnected client with stale state is often worse than a disconnected one. Treat disconnection as normal and design the recovery deliberately.
Scaling stateful connections
WebSocket connections are long-lived and stateful, which breaks the assumptions of stateless horizontal scaling. When you run multiple server instances, a message from a client on server A must reach a client connected to server B — servers no longer share memory. The standard pattern is a backplane: a pub/sub layer (commonly Redis) that servers publish to and subscribe from, so a message reaches every relevant client regardless of which instance holds their connection. Plan for this before you scale past one server, because retrofitting it under load is painful.
A persistent connection needs auth at establishment — validate a token during the handshake, do not trust an unauthenticated socket. But authentication at connect time is not enough: authorise each message and subscription against what that user is allowed to do, so a connected client cannot subscribe to channels or send messages beyond its permissions. A long-lived authenticated socket that skips per-action authorisation is a standing security hole.
Real-time with WebSockets is less about the protocol and more about the patterns: choose them only for genuine bidirectional needs (SSE or polling otherwise), build reconnection with backoff and state resync as a first-class concern, scale stateful connections with a pub/sub backplane, and authenticate at connect while authorising every message. Get those patterns right and WebSockets deliver reliable real-time; skip them and you get a demo that falls apart the moment a connection drops or you add a second server.
Independent software engineer in Nairobi specialising in Acumatica customisations, Laravel backends, and tax fiscalisation integrations across East and Southern Africa.