It was mostly a learning project for me, but I'm planning to do a write-up soon as a guide for Python developers moving to Elixir.

Re: ETS, I was just imagining something like Realtime but without Postgres, just using ETS. Most of the use cases I can think of for this type of thing don't require relational data, so I was thinking of just using ETS as a KV/document store to hold user and application state and then reacting to changes in to that the way you are here. I think you'd lose the benefits of relational queries and persistence but gain some function in overhead and decentralization. I'm moving to Elixir after spending a lot of time doing "serverless" and event-driven architectures, so now I'm spending a lot of time thinking about how to get the benefits of both worlds.