Switched my #Nix installation on #macOS from the original installer to the one by @determinatesystems. Since that one disables channels in favor of flakes by default, I also took the opportunity to use Nix more properly instead of just running nix-env -i when needed :'-)
Ended up looking at #nixDarwin, #HomeManager and #Fleek. To a complete newb like me the differences where rather hard to grasp
nix-darwin tries to replicate the feel of #NixOS on macOS – something I couldn't comprehend since I never ran NixOS. More generally though, in NixOS, Nix is used to manage the whole OS (duh) and defines the system-wide installed/configured packages/environment. As such, nix-darwin replicates this style of providing a system environment on macOS.
home-manager shifts this concept to a per-user basis. The configuration system is quite similar, just per-user.
#Fleek is a Go tool to generate home-manager configurations from YAML.
Now, you can also install home-manager as a nix-darwin (on macOS) or NixOS (on... NixOS) module, which allows upgrades of the homes through the system wide Nix upgrade process.
After I got myself a new (used) laptop, I started to checkout nix-darwin and kind of got lost for two weeks just tweaking my configuration every evening... after a lot of frustration in the first place, I now really love how nix works and let you configure a machine and your home folder in a reproducible way and in one language 👌🏽it doesn't solve everything, but I feel like it's more consistent now compared to my former dotfie repository