diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yml
similarity index 97%
rename from .github/workflows/build.yaml
rename to .github/workflows/build.yml
index 256acb6344b..7c99924ea83 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yml
@@ -57,7 +57,7 @@ jobs:
       - name: Upload build archive
         uses: actions/upload-artifact@v4
         with:
-          name: dists
+          name: dists-${{ github.ref }}
           path: |
             packages/**/dist
             repo-scripts/**/dist
@@ -74,7 +74,7 @@ jobs:
     - name: Download build archive
       uses: actions/download-artifact@v4
       with:
-        name: dists
+        name: dists-${{ github.ref }}
     - uses: actions/setup-node@v4
       with:
         node-version-file: '.nvmrc'
diff --git a/.github/workflows/test-all.yml b/.github/workflows/test-all.yml
index a3b3f5ca73c..672160b7f11 100644
--- a/.github/workflows/test-all.yml
+++ b/.github/workflows/test-all.yml
@@ -14,7 +14,11 @@
 
 name: Test All Packages
 
-on: pull_request
+on: 
+  workflow_run:
+    workflows: ["Build"]
+    types:
+      - completed
 
 env:
   # make chromedriver detect installed Chrome version and download the corresponding driver
@@ -30,43 +34,10 @@ env:
   NODE_OPTIONS: "--max_old_space_size=4096"
 
 jobs:
-  build:
-    name: Build the SDK
-    runs-on: ubuntu-latest
-    steps:
-    # Install Chrome so the correct version of webdriver can be installed by chromedriver when
-    # setting up the repo. This must be done to build and execute Auth properly.
-    - name: install Chrome stable
-      run: |
-        npx @puppeteer/browsers install chrome@stable
-    - uses: actions/checkout@v3
-    - name: Set up Node (20)
-      uses: actions/setup-node@v4
-      with:
-        node-version-file: '.nvmrc'
-    - name: Test setup and yarn install
-      run: |
-        cp config/ci.config.json config/project.json
-        yarn
-    - name: yarn build
-      run: yarn build
-    - name: Archive build
-      if: ${{ !cancelled() }}
-      run: |
-        tar -cf build.tar --exclude=.git .
-        gzip build.tar
-    - name: Upload build archive
-      if: ${{ !cancelled() }}
-      uses: actions/upload-artifact@v3
-      with:
-          name: build.tar.gz
-          path: build.tar.gz
-          retention-days: ${{ env.artifactRetentionDays }}
-        
   # Auth and Firestore are built and executed in their own jobs in an attempt to reduce flakiness.
   test-the-rest:
+    if: ${{ github.event.workflow_run.conclusion == 'success'}}
     name: (bulk) Node.js and Browser (Chrome) Tests
-    needs: build
     runs-on: ubuntu-latest
     steps:
     # install Chrome first, so the correct version of webdriver can be installed by chromedriver when setting up the repo
@@ -74,19 +45,23 @@ jobs:
       run: |
         npx @puppeteer/browsers install chrome@stable
     - name: Download build archive
-      uses: actions/download-artifact@v3
+      uses: actions/download-artifact@v4
       with:
-        name: build.tar.gz
-    - name: Unzip build artifact
-      run: tar xf build.tar.gz
-    - name: Set up Node (20)
-      uses: actions/setup-node@v4
+        name: dists-${{ github.ref }}
+    - uses: actions/setup-node@v4
       with:
         node-version-file: '.nvmrc'
-    - name: Test setup and yarn install
-      run: |
-        cp config/ci.config.json config/project.json
-        yarn
+        cache: yarn
+        cache-dependency-path: yarn.lock
+    - name: Restore cached node_modules
+      uses: actions/cache@v4
+      id: node_modules
+      with:
+        path: "**/node_modules"
+        key: node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+    - run: yarn install --frozen-lockfile
+    - name: Test setup
+      run: cp config/ci.config.json config/project.json
     - name: Set start timestamp env var
       run: echo "FIREBASE_CI_TEST_START_TIME=$(date +%s)" >> $GITHUB_ENV
     - name: Run unit tests
@@ -106,8 +81,8 @@ jobs:
       continue-on-error: true
 
   test-auth:
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}
     name: (Auth) Node.js and Browser (Chrome) Tests
-    needs: build
     runs-on: ubuntu-latest
     steps:
       # install Chrome first, so the correct version of webdriver can be installed by chromedriver
@@ -125,19 +100,23 @@ jobs:
       run: |
         echo $CHROME_VERSION_NOTES=$CHROME_VERSION_MISMATCH_MESSAGE
     - name: Download build archive
-      uses: actions/download-artifact@v3
+      uses: actions/download-artifact@v4
       with:
-        name: build.tar.gz
-    - name: Unzip build artifact
-      run: tar xf build.tar.gz
-    - name: Set up Node (20)
-      uses: actions/setup-node@v4
+        name: dists-${{ github.ref }}
+    - uses: actions/setup-node@v4
       with:
         node-version-file: '.nvmrc'
-    - name: Test setup and yarn install
-      run: |
-        cp config/ci.config.json config/project.json
-        yarn
+        cache: yarn
+        cache-dependency-path: yarn.lock
+    - name: Restore cached node_modules
+      uses: actions/cache@v4
+      id: node_modules
+      with:
+        path: "**/node_modules"
+        key: node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+    - run: yarn install --frozen-lockfile
+    - name: Test setup
+      run: cp config/ci.config.json config/project.json
     - name: Set start timestamp env var
       run: echo "FIREBASE_CI_TEST_START_TIME=$(date +%s)" >> $GITHUB_ENV
     - name: Run unit tests
@@ -156,8 +135,8 @@ jobs:
       continue-on-error: true
 
   test-firestore:
+    if: ${{ github.event.workflow_run.conclusion == 'success'}}
     name: (Firestore) Node.js and Browser (Chrome) Tests
-    needs: build
     runs-on: ubuntu-latest
     steps:
     # install Chrome so the correct version of webdriver can be installed by chromedriver when setting up the repo
@@ -165,19 +144,23 @@ jobs:
       run: |
         npx @puppeteer/browsers install chrome@stable
     - name: Download build archive
-      uses: actions/download-artifact@v3
+      uses: actions/download-artifact@v4
       with:
-        name: build.tar.gz
-    - name: Unzip build artifact
-      run: tar xf build.tar.gz
-    - name: Set up Node (20)
-      uses: actions/setup-node@v4
+        name: dists-${{ github.ref }}
+    - uses: actions/setup-node@v4
       with:
         node-version-file: '.nvmrc'
-    - name: Test setup and yarn install
-      run: |
-        cp config/ci.config.json config/project.json
-        yarn
+        cache: yarn
+        cache-dependency-path: yarn.lock
+    - name: Restore cached node_modules
+      uses: actions/cache@v4
+      id: node_modules
+      with:
+        path: "**/node_modules"
+        key: node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+    - run: yarn install --frozen-lockfile
+    - name: Test setup
+      run: cp config/ci.config.json config/project.json
     - name: Set start timestamp env var
       run: echo "FIREBASE_CI_TEST_START_TIME=$(date +%s)" >> $GITHUB_ENV
     - name: Run unit tests
@@ -196,12 +179,12 @@ jobs:
         path-to-lcov: ./lcov-all.info
       continue-on-error: true
   test-firestore-integration:
+    if: ${{ github.event.workflow_run.conclusion == 'success'}}
     strategy:
       fail-fast: false
       matrix:
         persistence: ['memory', 'persistence']
     name: Firestore Integration Tests (${{ matrix.persistence }})
-    needs: build
     runs-on: ubuntu-latest
     steps:
     # install Chrome so the correct version of webdriver can be installed by chromedriver when setting up the repo
@@ -209,17 +192,22 @@ jobs:
       run: |
         npx @puppeteer/browsers install chrome@stable
     - name: Download build archive
-      uses: actions/download-artifact@v3
+      uses: actions/download-artifact@v4
       with:
-        name: build.tar.gz
-    - name: Unzip build artifact
-      run: tar xf build.tar.gz
-    - name: Set up Node (20)
-      uses: actions/setup-node@v4
+        name: dists-${{ github.ref }}
+    - uses: actions/setup-node@v4
       with:
         node-version-file: '.nvmrc'
+        cache: yarn
+        cache-dependency-path: yarn.lock
+    - name: Restore cached node_modules
+      uses: actions/cache@v4
+      id: node_modules
+      with:
+        path: "**/node_modules"
+        key: node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+    - run: yarn install --frozen-lockfile
     - run: cp config/ci.config.json config/project.json
-    - run: yarn
     - run: yarn build:${{ matrix.persistence }}
       working-directory: integration/firestore
     - run: xvfb-run yarn karma:singlerun