Take this with a grain of salt.

I loved using NixOS with flakes, home-manager and custom minimalistic setup with XMonad or Sway. I was also using Nix with direnv whenever I could for my development projects. At the same time I’ve noticed that a lot of my programming focus (and time) was being used by solving niche issues with Nix, packaging things for Nix, suddenly breaking applications (because of upstream changes within nixpkgs). I’ve also had issues with using other ways of providing development environment (npm, pip stuff etc).

I was using unstable channel so breakages part is most likely on me. But apart from that I’m left with the feeling that NixOS is a huge time sink which isn’t necessarily worth it if you aren’t managing a whole fleet of machines.

Nowadays I am happy not using Nix at all. My development needs are fullfilled by what is available via dnf (Fedora package manager) and npm. I also use podman containers and flatpak a lot more since I’ve switched to Silverblue.