On the topic of build times, it took me too long to learn that nixos-rebuild supports remote build workers and targets.

For example, if I am editing on my laptop, want to build on my desktop, and apply the build to my file server, then I’d run…

me@laptop$ nixos-rebuild \
--flake ~/wherever-it-lives \
--build-host desktop \
--target-host file-server \
--use-remote-sudo

The host names should match the name of the nixosConfiguration output from your flake. If they don’t I think you can specify like, –target-host .#some-machine

Remote sudo avoids having to SSH as root.

Bonus tip: Having Tailscale on every machine makes this work reliably from anywhere, network speed as the limit.