The idea here is that this is a general discussion mega thread style post. Feel free to come in and ask questions, answer questions, and generally discuss.
This can go on as long as we want, and stay pinned if that works. We can simply using sorting to see the latest or “biggest” comments in here.
The worst bit about digging into a codebase, IMO, is orientating yourself and working out what does what!
The backend codebase can be found here: https://github.com/LemmyNet/lemmy
The “Contributing” section of the documentation (see here) lists how the other components of the platform interact with each other and the backend. But I don’t think there’s any outline of how the pieces of the backend work.
Perhaps another relevant codebase is the activity pub framework made along with lemmy: https://github.com/LemmyNet/activitypub-federation-rust.