Tracking Presence and Online Status
Build a real-time presence system that shows who is online, broadcasting connect/disconnect events and surfacing live user status.
What Is Presence?
Presence is knowing who is currently online: the green dots in chat apps, the live cursors in collaborative editors, the active-now lists. It is one of the most requested real-time features.
Presence Is About Lifecycle Events
The core insight: presence is derived from connection lifecycle. When a session opens, mark the user online; when it closes, mark them offline, then broadcast the change.
All lessons in this course
- Server-Sent Events (SSE) vs. WebSockets
- Real-Time Data Push Architectures
- Implementing User Notifications
- Tracking Presence and Online Status