Correct method for streaming / persistence

Deploy doesn't appear to support websocket hosting, and seems to be oriented around a request-based system. However, the chat example uses EventSource and a persistent connection, which seems to accomplish largely the same thing.

I'm not clear on the lifecycle of a deno deploy instance (e.g. what processes are running where), but are server-sent events the correct path forward for these uses, and/or how should we be thinking about persistence-style use-cases?