diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 00000000..c98ac953
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,58 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Build
+
+on:
+  push:
+    paths:
+      - 'app/**'
+      - 'functions/**'
+      - 'shared/**'
+  pull_request:
+    paths:
+      - 'app/**'
+      - 'functions/**'
+      - 'shared/**'
+
+env:
+  CI: true
+
+jobs:
+  unit:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version:
+          - 12.x
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Cache npm
+        uses: actions/cache@v1
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ matrix.node-version }}-${{ hashFiles('**/package-lock.json') }}
+
+      - name: Build Shared
+        run: (cd shared && npm install)
+
+      - name: Build App
+        run: (cd app && npm install && npm run build:production)
+
+      - name: Build Functions
+        run: (cd functions && npm install && npm run build)
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 0bdc2345..b160bd74 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -43,11 +43,5 @@ jobs:
       - name: Build Shared
         run: (cd shared && npm install)
 
-      - name: Build App
-        run: (cd app && npm install && npm run build:production)
-
-      - name: Build Functions
-        run: (cd functions && npm install && npm run build)
-
       - name: Validate Schemas
         run: (cd shared && npm run validate)