diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2b8d8a6..a63d5aa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -9,8 +9,7 @@ on:
 jobs:
   install-build:
     outputs:
-      foo-service: ${{ steps.install.outputs.foo-service }}
-      bar-service: ${{ steps.install.outputs.bar-service }}
+      job-strategy-matrix: ${{ steps.install.outputs.job-strategy-matrix }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
@@ -23,24 +22,20 @@ jobs:
           echo pnpm install
           node ./gen-service-version.js
 
-  foo-service:
+  build-services:
     needs: [install-build]
     runs-on: ubuntu-latest
-    if: ${{ needs.install-build.outputs.foo-service == 'run' }}
+    if: ${{ needs.install-build.outputs.job-strategy-matrix != '[""]' }}
+    strategy:
+      matrix:
+        service: ${{ fromJson(needs.install-build.outputs.job-strategy-matrix) }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
-      - name: Build
-        run: |
-          ./foo-service/build.sh
+        uses: gogaille/sparse-checkout@3114de9b3cf84c0829fe84222d8ae8d806fbc794
+        with:
+          patterns: '${{ matrix.service }} gen-service-version.js'
 
-  bar-service:
-    needs: [install-build]
-    runs-on: ubuntu-latest
-    if: ${{ needs.install-build.outputs.bar-service == 'run' }}
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v3
       - name: Build
         run: |
-          ./bar-service/build.sh
+          ls .
+          ./${{ matrix.service }}/build.sh
diff --git a/bar-service/bar.sh b/bar-service/bar.sh
index 019eb5d..89a1700 100755
--- a/bar-service/bar.sh
+++ b/bar-service/bar.sh
@@ -1,3 +1,5 @@
 #!/usr/bin/env bash
 
 echo 'running bar!'
+echo 'cool new feature -fixing feature'
+echo 'new feature'
diff --git a/foo-service/foo.sh b/foo-service/foo.sh
index 14338a5..8163df7 100755
--- a/foo-service/foo.sh
+++ b/foo-service/foo.sh
@@ -4,3 +4,5 @@ echo 'Running foo!'
 echo 'fixed bug'
 echo 'fixed another bug'
 echo 'NOT ANOTHER ONE'
+
+echo 'adding a thing here'
diff --git a/gen-service-version.js b/gen-service-version.js
index f4732cc..ef781ba 100644
--- a/gen-service-version.js
+++ b/gen-service-version.js
@@ -1,16 +1,14 @@
-const child_process = require("child_process");
+const child_process = require('child_process');
 
-const services = ["bar-service", "foo-service"];
+const services = ['bar-service', 'foo-service'];
 
 function latestCommitInDirectory(dirname) {
-  return String(
-    child_process.execSync(`git log --pretty=format:%H -n 1 ${dirname}`)
-  );
+  return String(child_process.execSync(`git log --pretty=format:%H -n 1 ${dirname}`));
 }
 
 const serviceVersions = {};
 
-const currentCommit = latestCommitInDirectory(".");
+const currentCommit = latestCommitInDirectory('.');
 
 for (const service of services) {
   serviceVersions[service] = latestCommitInDirectory(service);
@@ -19,8 +17,14 @@ for (const service of services) {
 console.log(currentCommit);
 console.log(serviceVersions);
 
+let job_strategy_matrix = [];
 Object.entries(serviceVersions).forEach(([name, version]) => {
-  const skip = version === currentCommit ? "run" : "skip";
+  const skip = version === currentCommit ? 'run' : 'skip';
 
-  console.log(`::set-output name=${name}::${skip}`);
+  console.log(`${name}::${skip}`);
+  if (version === currentCommit) {
+    job_strategy_matrix.push(name);
+  }
 });
+
+console.log(`::set-output name=job-strategy-matrix::["${job_strategy_matrix.join('", "')}"]`);