BackendFrontendFull-StackAround since 2006
Server-Sent Events
Also written as SSE, EventSource
A one-way stream from server to browser for live updates. Simpler than WebSockets, and what most AI chat interfaces use to stream a reply word by word.
Think of it like
A ticker tape running into the room. It only goes one way, which is all the news needs.
Junior or senior?
Increasingly relevant on LLM products.
Senior sounds like
Can explain why they chose it over WebSockets, usually simplicity and surviving corporate proxies.
Ask them
“Why server-sent events rather than WebSockets for that feature?”