I'm not OP but that's basically right. With NixOS, nix generates the system configuration as well as making sure the packages are available. If you pin your dependencies using something like nix flakes and rely on git as your source of truth, you can get GitOps for the operating system.

But it isn't necessary. You can certainly make a change and apply it without committing it to git or relying on a CI/CD pipeline to deploy it. And it isn't necessary to use input pinning - if you don't, you can wind up making it at best archaeological work to rollback. Most people recommend flakes nowadays though, whose input pinning and purity rules should prevent any need for archaeology if you do commit before applying.

Yes. That's why I'm using NixOS as well, despite all the terrible jank it has.

Automating my homelab config with coding machines not only hides the jank, but also makes NixOS feel like some actual agentic OS Microsoft wants, or rather an ad-hoc prototype. I literally just tell it what to do and describe issues if I have any. But again I have written a ton of Nix previously and I'm able to verify what it does, most of the time it's correct but it's not perfect.