My First Impressions of Nix
&gt; Nix, on the other hand, does have a concept of state. If you make a one-line change to a 200-line Nix configuration, it doesn’t have to re-do all the work from the other 199 lines. It can evaluate the state of the system against the configuration file and recognize that it just has to apply the one-line change. And that change usually happens in a few seconds.<p>The author seems to have some misguided ideas about Nix. Nix is not fast because it is stateful. It is fast because it is functional and reproducible, which allows for caching without compromising correctness. I don&#x27;t want to split hairs, but referentially transparent caching like this is not quite what I&#x27;d call state.<p>Yes, there is some statefulness in system activation, but this is not what makes Nix Nix -- quite the opposite.