{
  lenovo = {
    hostname = "lenovo";
    system = "x86_64-linux";
    users = ["andromeda"];
    modules = [
      # impermanence
      ./modules/nixos/impermanence.nix
      ./modules/nixos/impermanence-ssh.nix

      # hardware configuration
      # includes `system.stateVersion`
      ./modules/nixos/machines/lenovo.nix

      # boot process
      # systemd-boot
      ./modules/nixos/boot/lenovo.nix

      # networking
      ./modules/nixos/laptop.nix

      # ly display manager
      ./modules/nixos/ly.nix

      # sway window manager
      ./modules/nixos/sway.nix

      # apps
      ./modules/nixos/steam.nix
    ];
  };
  "109-199-104-83" = {
    hostname = "109-199-104-83";
    system = "x86_64-linux";
    users = [];
    modules = [
      # impermanence
      ./modules/nixos/impermanence.nix
      ./modules/nixos/impermanence-ssh.nix

      # hardware configuration
      # verbatim as `nixos-generate-config` AND `system.stateVersion`
      ./modules/nixos/machines/109-199-104-83.nix
      ./modules/nixos/disko/remote.nix

      # boot process
      # grub boot on /dev/sda
      ./modules/nixos/boot/109-199-104-83.nix

      # networking
      ./modules/nixos/networking/domains/galaxious.de.nix
      # uses cloud-init to network
      ./modules/nixos/networking/networks/109-199-104-83.nix

      # ssh through port 5522 among other things
      # andromeda@lenovo is the only user allowed access
      # ./modules/nixos/networking/hard-ssh.nix
      #./modules/nixos/networking/ssh-as-root.nix
      ({config, ...}: {
        services.openssh.enable = true;
        users.users.root.openssh.authorizedKeys.keys = [config.pub-keys.ssh.andromeda];
      })

      # TODO add Impermanence to the following services

      # simple-nixos-mailserver email server
      # mail.domain
      ./modules/nixos/mailserver.nix

      # roundcube webmail client
      # webmail.domain
      # ./modules/nixos/roundcube.nix

      # zulip chat client
      # chat.domain
      # zulip chat server
      # zulip.domain
      # ./modules/nixos/zulip.nix
    ];
  };
}