[XCSme]

> I ideally just want to write my game’s backend logic and have everything else (spinning up servers, load balancing, containers, etc) handled for me

My advice is to just make the game, and implement the simplest backend possible (using a basic server/VPS) without worrying about scaling at all.

What type of game is it?

> I would make an api request to have that player move forward, the request would update the player’s location in the real-time db, and all other players would be notified and updated of the movement.

You can store all this data in memory of the server running the game loop. Note that you need a server, otherwise the game would be client-authoritative, so prone to cheating/hacking/desyncs.

I would suggest creating a Node.js server on a VPS and using web sockets for communication.