So, nix actually tries to solve the problem of "what are your dependencies, how are they declared, how are interdependent parts related to each other?" where docker just goes "screw it. nobody's ever going to be able to tame this tangle. let's just throw it all in behind an os container and let it do what it wants"

I've recently nixified the (really very complicated) deployment of our main webapp at work and I now have the entire setup of the webapp defined in about 5 .nix files. That's a really relaxing place to be in (compared to how things were before).