Why?

Why? Why on self-host all your own infrastructure?

We tried not to, at the very beginning of the project. We agreed that Github-style code review wasn't really fit for our kind of project, and wanted to use Gerrit for code review. We started setting up Gerrithub for a repo hosted on Github, and we ran into so many problems with that approach that it was actually easier to just self-host Gerrit instead. Then there was little reason to use Github too, since none of us are really happy with Github direction lately anyway, and Forgejo + Github-enabled SSO mean that contributors shouldn't have to jump through too many hoops to help out.

So now we have a fully independent and open source infrastructure stack, with (hopefully) a good onboarding path as well. And we're also in our own critical path: we run into Nix's papercuts and gashes alike every day, so we better fix it!