We maintain a fork of Godot ~3.5. We have a netcode module that we coded in c++ that does client side prediction and rollback. It uses websockets under the hood on the web client, enet on native clients.
We use Agones on Kubernetes to allocate game servers, those servers run godot itself which runs the game.
Custom coded golang matchmaker which makes the agones api call to allocate a server when needed.
We use contour & nginx to route web traffic and serve a .html file.
We use github actions to deploy to various environments.
We use heroic labs' open source thing called nakama as a base for our account/auth backend.
We have a bunch of other k8s stuff in the cluster for various small pieces but thats about the crux of it!