Glossary term
What is SSE (Server-Sent Events)?
SSE stands for Server-Sent Events.
In System Design
A one-way stream of updates from server to browser over HTTP. Example: AI answers appearing word by word; live scores.
Learn it properly · System DesignLesson 33: Real-Time Apps: Polling, WebSockets and SSEHTTP only lets the client ask. For “new message”, “rider is nearby” or an AI answer streaming in, the server has to push. Short polling, long polling, Server-Sent Events and WebSockets compared — and how to scale millions of open connections.In Practical Design Problems
A one-way stream from the server to the browser over HTTP. It reconnects by itself and can resume with Last-Event-ID.
Learn it properly · Practical Design ProblemsLesson 5: Design a Notification System (In-App, Push, Email)Polling, long polling, server-sent events and WebSockets, fan-out with queues, read state, user settings, retries and removing duplicates.In Networking for Developers
A plain HTTP response that stays open so the server can push text events to the browser.
Learn it properly · Networking for DevelopersLesson 7: WebSockets, Server-Sent Events and Real-Time NetworkingPolling versus long polling, WebSockets, SSE, scaling real-time connections, and a working example of each.