diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b2be92b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+result
diff --git a/buildbot_nix/master.py b/buildbot_nix/master.py
index 51a7cc1..b48c560 100644
--- a/buildbot_nix/master.py
+++ b/buildbot_nix/master.py
@@ -44,6 +44,7 @@ BUILDBOT_URL = os.environ["BUILDBOT_URL"]
 BUILDBOT_GITHUB_USER = os.environ["BUILDBOT_GITHUB_USER"]
 NIX_SUPPORTED_SYSTEMS = os.environ["NIX_SUPPORTED_SYSTEMS"].split(" ")
 NIX_EVAL_MAX_MEMORY_SIZE = int(os.environ.get("NIX_EVAL_MAX_MEMORY_SIZE", "4096"))
+BUILDBOT_DB_URL = os.environ.get("DB_URL", "sqlite:///state.sqlite")
 
 
 def config_for_project(
@@ -225,7 +226,7 @@ def build_config() -> dict[str, Any]:
         ),
     }
 
-    c["db"] = {"db_url": os.environ.get("DB_URL", "sqlite:///state.sqlite")}
+    c["db"] = {"db_url": BUILDBOT_DB_URL}
 
     c["protocols"] = {"pb": {"port": "tcp:9989:interface=\\:\\:"}}
     c["buildbotURL"] = BUILDBOT_URL
diff --git a/buildbot_nix/worker.py b/buildbot_nix/worker.py
index 1bb8d5b..7e1181e 100644
--- a/buildbot_nix/worker.py
+++ b/buildbot_nix/worker.py
@@ -3,6 +3,7 @@
 import multiprocessing
 import os
 import socket
+from dataclasses import dataclass
 from pathlib import Path
 
 from buildbot_worker.bot import Worker
@@ -15,13 +16,20 @@ def require_env(key: str) -> str:
     return val
 
 
-PASSWD = Path(require_env("WORKER_PASSWORD_FILE")).read_text().strip("\r\n")
-BUILDBOT_DIR = require_env("BUILDBOT_DIR")
-MASTER_URL = require_env("MASTER_URL")
+@dataclass
+class WorkerConfig:
+    password: str = Path(require_env("WORKER_PASSWORD_FILE")).read_text().rstrip("\r\n")
+    worker_count: int = int(
+        os.environ.get("WORKER_COUNT", str(multiprocessing.cpu_count()))
+    )
+    buildbot_dir: str = require_env("BUILDBOT_DIR")
+    master_url: str = require_env("MASTER_URL")
 
 
-def setup_worker(application: service.Application, id: int) -> None:
-    basedir = f"{BUILDBOT_DIR}-{id}"
+def setup_worker(
+    application: service.Application, id: int, config: WorkerConfig
+) -> None:
+    basedir = f"{config.buildbot_dir}-{id}"
     os.makedirs(basedir, mode=0o700, exist_ok=True)
 
     hostname = socket.gethostname()
@@ -36,10 +44,10 @@ def setup_worker(application: service.Application, id: int) -> None:
         None,
         None,
         workername,
-        PASSWD,
+        config.password,
         basedir,
         keepalive,
-        connection_string=MASTER_URL,
+        connection_string=config.master_url,
         umask=umask,
         maxdelay=maxdelay,
         numcpus=numcpus,
@@ -50,9 +58,12 @@ def setup_worker(application: service.Application, id: int) -> None:
     s.setServiceParent(application)
 
 
+def setup_workers(application: service.Application, config: WorkerConfig) -> None:
+    for i in range(config.worker_count):
+        setup_worker(application, i, config)
+
+
 # note: this line is matched against to check that this is a worker
 # directory; do not edit it.
 application = service.Application("buildbot-worker")
-
-for i in range(multiprocessing.cpu_count()):
-    setup_worker(application, i)
+setup_workers(application, WorkerConfig())
diff --git a/examples/default.nix b/examples/default.nix
index 30638b7..2ee51bf 100644
--- a/examples/default.nix
+++ b/examples/default.nix
@@ -1,4 +1,4 @@
-{ nixpkgs, system, srvos, buildbot-nix, disko, ... }:
+{ nixpkgs, system, buildbot-nix, ... }:
 let
   # some example configuration to make it eval
   dummy = { config, modulesPath, ... }: {
@@ -15,7 +15,7 @@ let
   inherit (lib) nixosSystem;
 in
 {
-  example-master = nixosSystem {
+  "example-master-${system}" = nixosSystem {
     inherit system;
     modules = [
       dummy
@@ -44,7 +44,7 @@ in
       buildbot-nix.nixosModules.buildbot-master
     ];
   };
-  example-worker = nixosSystem {
+  "example-worker-${system}" = nixosSystem {
     inherit system;
     modules = [
       dummy
diff --git a/flake.nix b/flake.nix
index 7e80f5a..311c696 100644
--- a/flake.nix
+++ b/flake.nix
@@ -9,28 +9,36 @@
   };
 
   outputs = inputs@{ self, flake-parts, ... }:
-    flake-parts.lib.mkFlake { inherit inputs; } ({ lib, ... }: {
-      systems = [ "x86_64-linux" ];
-      flake = {
-        nixosModules.buildbot-master = ./nix/master.nix;
-        nixosModules.buildbot-worker = ./nix/worker.nix;
+    flake-parts.lib.mkFlake { inherit inputs; } ({ lib, ... }:
+      {
+        systems = [ "x86_64-linux" "aarch64-linux" ];
+        flake = {
+          nixosModules.buildbot-master = ./nix/master.nix;
+          nixosModules.buildbot-worker = ./nix/worker.nix;
 
-        nixosConfigurations = import ./examples {
-          inherit (inputs) nixpkgs srvos disko;
-          buildbot-nix = self;
-          system = "x86_64-linux";
+          nixosConfigurations =
+            let
+              examplesFor = system: import ./examples {
+                inherit system;
+                inherit (inputs) nixpkgs;
+                buildbot-nix = self;
+              };
+            in
+            examplesFor "x86_64-linux" // examplesFor "aarch64-linux";
         };
-        checks.x86_64-linux = {
-          nixos-master = self.nixosConfigurations.example-master.config.system.build.toplevel;
-          nixos-worker = self.nixosConfigurations.example-worker.config.system.build.toplevel;
+        perSystem = { self', pkgs, system, ... }: {
+          packages.default = pkgs.mkShell {
+            packages = [
+              pkgs.bashInteractive
+            ];
+          };
+          checks =
+            let
+              nixosMachines = lib.mapAttrs' (name: config: lib.nameValuePair "nixos-${name}" config.config.system.build.toplevel) ((lib.filterAttrs (_: config: config.pkgs.system == system)) self.nixosConfigurations);
+              packages = lib.mapAttrs' (n: lib.nameValuePair "package-${n}") self'.packages;
+              devShells = lib.mapAttrs' (n: lib.nameValuePair "devShell-${n}") self'.devShells;
+            in
+            nixosMachines // packages // devShells;
         };
-      };
-      perSystem = { pkgs, system, ... }: {
-        packages.default = pkgs.mkShell {
-          packages = [
-            pkgs.bashInteractive
-          ];
-        };
-      };
-    });
+      });
 }