{
  description = "Project dev shell";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

  outputs = { self, nixpkgs }:
    let
      systems = [ "x86_64-linux" "aarch64-linux" ];
      forAllSystems = nixpkgs.lib.genAttrs systems;
    in
    {
      devShells = forAllSystems (system:
        let
          pkgs = nixpkgs.legacyPackages.${system};
        in
        {
          default = pkgs.mkShell {
            packages = with pkgs; [
              # Add per-project tools here.
              # Example: nodejs_22 python313 cargo gcc
            ];

            shellHook = ''
              # Per-project env setup (printed once on shell entry).
            '';
          };
        });
    };
}