WebSockets for Vercel Functions: How We Built It

It's really interesting to see this essentially providing a stateful wrapper around scalable serverless compute. Restate does something similar, where the restate service "farms out" work to e.g. Lambda. As a whole the system implements a durable, stateful process - but it can leverage these stateless compute systems to do so.

https://docs.restate.dev/foundations/key-concepts