{
  lib,
  nixpkgs,
  inputs,
  self,
  ...
}:
rec {
  getDirs =
    parentDir:
    lib.mapAttrs (n: v: (import "${parentDir}/${n}")) (
      lib.filterAttrs (n: v: v == "directory") (builtins.readDir parentDir)
    );
  loadInstances =
    dir: extraModules: lib.mapAttrs (n: v: loadInstance extraModules v (getDirs dir)) (getDirs dir);
  loadInstance =
    extraModules: instance: instanceConfigs:
    nixpkgs.lib.nixosSystem {
      specialArgs = {
        inherit inputs instanceConfigs;
        instanceConfig = instance;
      };
      modules =
        instance.modules
        ++ extraModules
        ++ [
          (
            { pkgs, ... }:
            {

              nixpkgs.overlays = [
                (final: prev: {
                  inherit (final.unstable.lixPackageSets.latest)
                    nixpkgs-review
                    nix-direnv
                    nix-eval-jobs
                    nix-fast-build
                    colmena
                    ;
                })
              ];

              nix.package = pkgs.unstable.lixPackageSets.latest.lix;
            }
          )
          (
            { pkgs, ... }:
            {
              nixpkgs.overlays = [
                self.overlays.default
              ];
              nixpkgs.config.allowUnfree = true;
              networking.hostName = instance.hostName;
            }
          )
        ];
    };
}