beyond the session protocol, you have to think about the bundle of state you need to carry between requests in a _clean_ way (preferably something that goes bey

beyond the session protocol, you have to think about the bundle of state you need to carry between requests in a _clean_ way (preferably something that goes beyond "stuff it in the session dict", because that's basically global variables). You also most likely want ways to do things like fetch non-stale versions of objects from the DB, help with certain data assertions, etc. You don't need to have a stateless backend for horizontal scale, you can have relatively smart routing, or relying on stuff like the database to help you with the coordination. Especially if you do things like say "this session is held to for up to an hour" you could even consider suspending VMs! If you have the resources to do so, that is. I think that "coupling frontend and backend" is not really what is being requested here, but more about providing functionality that lets you build rich backends based on the fact that our frontends are way richer than they used to be