real-time subscriptions

Real-time subscriptions eliminate polling by pushing instant data updates to clients via persistent WebSocket connections.

Real-time subscriptions replace the inefficient 'request-response' cycle with a push-based model that delivers data the millisecond it changes. By maintaining open WebSocket or SSE connections, platforms like Ably and Pusher allow thousands of concurrent users to receive live updates without taxing the server through constant polling. This technology is the backbone of modern collaborative tools like Figma, live sports tickers, and high-frequency trading dashboards where a 500ms delay is a failure. It ensures state synchronization across distributed systems, keeping every connected device in lockstep with the primary data source.

https://www.ably.com/realtime-subscriptions