I found reading code from Nixpkgs to be very valuable as well, and can't recommend it enough. I managed to get by using NixOS without writing my own derivations

I found reading code from Nixpkgs to be very valuable as well, and can't recommend it enough. I managed to get by using NixOS without writing my own derivations for several months until I inevitably ran into a need to package something new. Even then, Nix Pills isn't a super useful reference, it's sort of like learning Git by understanding blobs, too focused on details. Another pain point is looking for documentation of Nix library functions, I've solved this by using Manix[0] [0] https://github.com/mlvzk/manix https://github.com/mlvzk/manix