If you haven’t already, take a look at Elixir, and the Phoenix framework. Phoenix has excellent WebSocket integration which is probably what you’ll want for a multi-player game. You can also easily spin up a GenServer to act as the game server, but I guess that’s all a bit in the future
, worth considering though.
If you do decide to go the Elixir/Phoenix route then I’d recommend this course, Multi-Player Game
with Elixir, Phoenix, Vue & Elm by The Pragmatic Studio.
