That's the frontend code, it doesn't include the backend API services, which are closed source.
the backend (the AppView) can be found here:
https://github.com/bluesky-social/atproto/tree/main/packages...
there are various supporting services written in Go as well
Which is what I said in the second sentence
AppView is a specific term of art within the Bluesky federation architecture: https://atproto.com/guides/glossary#app-view, you were incorrect in identifying the public frontend repo as the AppView.
The glossary specifically calls out the UI as part of an app view. Can you explain why it is not according to you?
A frontend is (can be) part of an App View. It is quite literally the app you view the network through. There can also be headless app views and app views which have no backend