For simple devshell environments, you probably don't need to write much Nix at all. You can use a tool like numtide/devshell [1] to create a flake from a template which lets you define packages and commands you want to expose via a TOML config file.

[1] https://github.com/numtide/devshell/blob/master/docs/getting...

The reason to use the Flake based version is that then it will automatically create a flake.lock file which should be added to version control so every user will use the same nixpkgs version.

While you can build normal Dockerfiles using some Nix tools it would be the same as building the image from Docker directly. If you want the same package-pinning guarantees in Docker images, then you need to build a NixOS based image which will let you add Nix packages. The pkgs.dockerTools.buildLayeredImage and it's counterpart function pkgs.dockerTools.streamLayeredImage, are interesting in that they will build a layered docker image so that packages can be shared between containers which makes rebuilding images much faster. [2]

At some point you will probably want to manage the project's Go and Node dependencies themselves from Nix and that involve writing Nix. Essentially the process is to use a tool that convert's the go.mod and node/yarn lock file into a .nix file [3,4]. This can be a bit more involved as some dependencies especially nodejs ones will want to download additional resources at build time which breaks the Nix model.

The best way to use Nix is gradually; just start with a simple devshell. There are some oddities when using Nix on Mac so it's best to get those figured out before trying to do too much.

[2] https://nixos.org/manual/nixpkgs/stable/#ssec-pkgs-dockerToo... [3] https://nixos.wiki/wiki/Go [4] https://nixos.wiki/wiki/Node.js