diff --git a/README.md b/README.md
index fb9c036..1ce1a22 100644
--- a/README.md
+++ b/README.md
@@ -51,6 +51,7 @@ Start from `flake.nix` (see [Flakes](https://nixos.wiki/wiki/Flakes)). [`flake-p
 - `users`: user information
 - `secrets.json` (and `.sops.yaml`):  sops-nix secrets
 - `systems`: top-level configuration.nix('ish) for various systems
+- `clusters`: Features that span more than 1 system
 
 ## Tips
 
diff --git a/clusters/github-runner/darwin-module.nix b/clusters/github-runner/darwin-module.nix
new file mode 100644
index 0000000..692c3de
--- /dev/null
+++ b/clusters/github-runner/darwin-module.nix
@@ -0,0 +1,22 @@
+{ pkgs, ... }:
+
+{
+  # Github runner CI
+  users = {
+    knownUsers = [ "github-runner" ];
+    forceRecreate = true;
+    users.github-runner = {
+      uid = 1009;
+      description = "GitHub Runner";
+      home = "/Users/github-runner";
+      createHome = true;
+      shell = pkgs.bashInteractive;
+      # NOTE: Go to macOS Remote-Login settings and allow all users to ssh.
+      openssh.authorizedKeys.keys = [
+        # github-runner VM's /etc/ssh/ssh_host_ed25519_key.pub
+        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJUJvyuUnIs2q2TkJq29wqJ6HyOAeMmIK8PcH7xAlpVY root@github-runner"
+      ];
+    };
+  };
+  nix.settings.trusted-users = [ "github-runner" ];
+}
diff --git a/clusters/github-runner/nixos-module.nix b/clusters/github-runner/nixos-module.nix
new file mode 100644
index 0000000..4ef58b4
--- /dev/null
+++ b/clusters/github-runner/nixos-module.nix
@@ -0,0 +1,54 @@
+{ flake, pkgs, lib, ... }:
+
+let
+  inherit (flake) inputs;
+  inherit (inputs) self;
+  user = "github-runner";
+  group = "github-runner";
+  tokenFile = "/run/keys/github-runner-token.secret"; # See colmena keys in top-level flake.nix
+  # Convenient function to create multiple runners per single personal repo.
+  mkPersonalRunners = user:
+    lib.concatMapAttrs (repoName: meta:
+      lib.listToAttrs (lib.flip builtins.map (lib.range 1 meta.num) (idx:
+        let
+          name = "${repoName}-${builtins.toString idx}";
+        in
+        lib.nameValuePair name {
+          inherit user group tokenFile name;
+          enable = true;
+          replace = true;
+          extraPackages = with pkgs; [
+            coreutils
+            nixci
+          ];
+          url = "https://github.com/${user}/${repoName}";
+        })));
+  hostIP = "10.37.129.2"; # Find out using `ifconfig` on host, looking for bridge101
+in
+{
+
+  # User
+  users.users.${user} = {
+    inherit group;
+    isSystemUser = true;
+  };
+  users.groups.${group} = { };
+  nix.settings.trusted-users = [ user ];
+
+  # Runners
+  services.github-runners = mkPersonalRunners "srid" {
+    perpetuum.num = 2;
+  };
+
+  # macOS remote builder
+  nix.distributedBuilds = true;
+  nix.buildMachines = [{
+    hostName = hostIP;
+    systems = [ "aarch64-darwin" "x86_64-darwin" ];
+    # supportedFeatures = [ "kvm" "benchmark" "big-parallel" ];
+    maxJobs = 6; # 6 cores
+    protocol = "ssh-ng";
+    sshUser = user;
+    sshKey = "/etc/ssh/ssh_host_ed25519_key";
+  }];
+}
diff --git a/systems/darwin.nix b/systems/darwin.nix
index 74ee6ca..610b17a 100644
--- a/systems/darwin.nix
+++ b/systems/darwin.nix
@@ -1,32 +1,17 @@
 { pkgs, flake, ... }:
 
-# See nix-darwin/default.nix for other modules in use.
+let
+  inherit (flake) inputs;
+  inherit (inputs) self;
+in
 {
   imports = [
-    flake.inputs.self.darwinModules.default
-    ../nix-darwin/ci/github-runner.nix
-    ../nix-darwin/zsh-completion-fix.nix
+    self.darwinModules.default
+    "${self}/nix-darwin/ci/github-runner.nix"
+    "${self}/nix-darwin/zsh-completion-fix.nix"
+    "${self}/clusters/github-runner/darwin-module.nix"
   ];
 
-  # Github runner CI
-  users = {
-    knownUsers = [ "github-runner" ];
-    forceRecreate = true;
-    users.github-runner = {
-      uid = 1009;
-      description = "GitHub Runner";
-      home = "/Users/github-runner";
-      createHome = true;
-      shell = pkgs.bashInteractive;
-      # NOTE: Go to macOS Remote-Login settings and allow all users to ssh.
-      openssh.authorizedKeys.keys = [
-        # github-runner VM's /etc/ssh/ssh_host_ed25519_key.pub
-        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJUJvyuUnIs2q2TkJq29wqJ6HyOAeMmIK8PcH7xAlpVY root@github-runner"
-      ];
-    };
-  };
-  nix.settings.trusted-users = [ "github-runner" ];
-
   nixpkgs.hostPlatform = "aarch64-darwin";
 
   environment.systemPackages = with pkgs; [
diff --git a/systems/github-runner.nix b/systems/github-runner.nix
index 8cd3a7c..aaf3255 100644
--- a/systems/github-runner.nix
+++ b/systems/github-runner.nix
@@ -1,36 +1,8 @@
-# TODO: WIP
-# - [x] Intial config
-# - [x] Colmena deploy, with keys from 1Password.
-# - [x] Github Runners
-# - [x] Distributed builder to host (macOS)
-# - [x] Refactor, to allow multiple repos (then remove easy-github-runners.nix)
-# - [ ] Refactor into own dir
 { flake, pkgs, lib, ... }:
 
 let
   inherit (flake) inputs;
   inherit (inputs) self;
-  user = "github-runner";
-  group = "github-runner";
-  tokenFile = "/run/keys/github-runner-token.secret"; # See colmena keys in top-level flake.nix
-  # Convenient function to create multiple runners per single personal repo.
-  mkPersonalRunners = user:
-    lib.concatMapAttrs (repoName: meta:
-      lib.listToAttrs (lib.flip builtins.map (lib.range 1 meta.num) (idx:
-        let
-          name = "perpetuum-${builtins.toString idx}";
-        in
-        lib.nameValuePair name {
-          inherit user group tokenFile name;
-          enable = true;
-          replace = true;
-          extraPackages = with pkgs; [
-            coreutils
-            nixci
-          ];
-          url = "https://github.com/${user}/${repoName}";
-        })));
-  hostIP = "10.37.129.2"; # Find out using `ifconfig` on host, looking for bridge101
 in
 {
   imports = [
@@ -40,6 +12,7 @@ in
     "${self}/nixos/nix.nix"
     "${self}/nixos/self/primary-as-admin.nix"
     "${self}/nixos/server/harden/basics.nix"
+    "${self}/clusters/github-runner/nixos-module.nix"
   ];
 
   system.stateVersion = "23.11";
@@ -53,27 +26,4 @@ in
     };
   };
   services.openssh.enable = true;
-
-  # Runners
-  users.users.${user} = {
-    inherit group;
-    isSystemUser = true;
-  };
-  users.groups.${group} = { };
-  nix.settings.trusted-users = [ user ];
-  services.github-runners = mkPersonalRunners "srid" {
-    perpetuum.num = 2;
-  };
-
-  # macOS remote builder
-  nix.distributedBuilds = true;
-  nix.buildMachines = [{
-    hostName = hostIP;
-    systems = [ "aarch64-darwin" "x86_64-darwin" ];
-    # supportedFeatures = [ "kvm" "benchmark" "big-parallel" ];
-    maxJobs = 6; # 6 cores
-    protocol = "ssh-ng";
-    sshUser = user;
-    sshKey = "/etc/ssh/ssh_host_ed25519_key";
-  }];
 }