What does HackerNews think of realtime?
Listen to your to PostgreSQL database in realtime via websockets. Built with Elixir.
https://github.com/supabase/realtime
Spin up a Supabase database and then subscribe to changes with WebSockets.
You can play with it here once you have a db: https://realtime.supabase.com/inspector/new
Also, what was the reason not to go with Gevent?
Background/announcement: https://supabase.com/blog/supabase-realtime-multiplayer-gene...
Their stack is primarily comprised of other independent open source projects. The one component that isn't is their "realtime" server that serves updates from postgres' WAL over websockets, but that is open sourced[0] under Apache 2.0. From my understanding the primary part that has not been open sourced is their database browser / web UI. There are plenty of alternative management tools for postgres though. As you can export your database what else would you need to ensure your portability and independence?
Granted they make their docs fairly opaque for trying to self host. Presumably to encourage you to just use their hosted service. Hosting open sourced projects seems like a very ecosystem friendly way of monetizing.
We plan to move all the code over to https://github.com/supabase/realtime in the next couple of weeks and you'll be able to see the code in its entirety.