Except for my home directory, I have a little bit state on my machine, ssh host keys, WiFi credentials, journal logs (I almost want to remove this, but I bet that would bite me in the ass one day)

The root partition is a tmpfs ram disk, and everything not saved in a separate partition, and either mounted or symlinked on to my root partition is lost at shutdown and regenerated at boot. Its less than a second extra to boot, and it uses about 16MB extra memory. Everything is made very convenient through the impermanence nix module and the sops nix module