I think backend will move more towards streaming endpoints (WebSockets). Already with concepts such as Observables we're building apps entirely around streams o

I think backend will move more towards streaming endpoints (WebSockets). Already with concepts such as Observables we're building apps entirely around streams of events. So to me the connection between frontend and backend will just be what you already use to communicate between your app components (streams). With regards to "where the backend is", it doesn't really matter. It can be on N different servers. What's important is that we'll be able to generalize lots of logic and automate most of the things (things like auth, database writes/reads, etc). Other more specific things we'll always have to write ourselves, but the management of an "actual server" will be more and more abstracted, and we'll eventually deal with it entirely on the app-code side of things.