diff --git a/.github/workflows/runtime_build.yml b/.github/workflows/runtime_build.yml
index a380c2c85c722..80a8757948e45 100644
--- a/.github/workflows/runtime_build.yml
+++ b/.github/workflows/runtime_build.yml
@@ -26,7 +26,7 @@ jobs:
         id: define_release_channels
         with:
           script: |
-            return ['stable', 'experimental'];
+            return ["stable", "experimental"];
 
   build:
     name: yarn build
@@ -51,12 +51,14 @@ jobs:
           key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: yarn build --b=${{ matrix.bundle_type }} --r=${{ matrix.release_channel }} --ci=github
+      - name: Display structure of build
+        run: ls -R build
       - name: Archive build
         uses: actions/upload-artifact@v4
         with:
-          name: ${{ matrix.bundle_type }}-${{ matrix.release_channel }}
+          name: ${{ matrix.bundle_type }}_${{ matrix.release_channel }}
           path: |
-            build/**
+            build
 
   lint_build:
     name: yarn lint-build
@@ -65,6 +67,7 @@ jobs:
       matrix:
         bundle_type: ${{ fromJSON(needs.define_build_params.outputs.bundle_type) }}
         release_channel: ${{ fromJSON(needs.define_build_params.outputs.release_channel) }}
+    continue-on-error: true
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -79,9 +82,72 @@ jobs:
         with:
           path: "**/node_modules"
           key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+      - run: yarn install --frozen-lockfile
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
-          name: ${{ matrix.bundle_type }}-${{ matrix.release_channel }}
-      - run: yarn install --frozen-lockfile
+          name: ${{ matrix.bundle_type }}_${{ matrix.release_channel }}
+          path: build
+      - name: Display structure of build
+        run: ls -R build
       - run: yarn lint-build
+
+  test_build:
+    name: yarn test-build
+    needs: build
+    strategy:
+      matrix:
+        test_params: [
+          # Intentionally passing these as strings instead of creating a
+          # separate parameter per CLI argument, since it's easier to
+          # control/see which combinations we want to run.
+          -r=stable --env=development,
+          -r=stable --env=production,
+          -r=experimental --env=development,
+          -r=experimental --env=production,
+
+          # Dev Tools
+          --project=devtools -r=experimental,
+
+          # TODO: Update test config to support www build tests
+          # - "-r=www-classic --env=development --variant=false"
+          # - "-r=www-classic --env=production --variant=false"
+          # - "-r=www-classic --env=development --variant=true"
+          # - "-r=www-classic --env=production --variant=true"
+          # - "-r=www-modern --env=development --variant=false"
+          # - "-r=www-modern --env=production --variant=false"
+          # - "-r=www-modern --env=development --variant=true"
+          # - "-r=www-modern --env=production --variant=true"
+
+          # TODO: Update test config to support xplat build tests
+          # - "-r=xplat --env=development --variant=false"
+          # - "-r=xplat --env=development --variant=true"
+          # - "-r=xplat --env=production --variant=false"
+          # - "-r=xplat --env=production --variant=true"
+
+          # TODO: Test more persistent configurations?
+        ]
+    continue-on-error: true
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 18.x
+          cache: "yarn"
+          cache-dependency-path: yarn.lock
+      - name: Restore cached node_modules
+        uses: actions/cache@v4
+        id: node_modules
+        with:
+          path: "**/node_modules"
+          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+      - run: yarn install --frozen-lockfile
+      - name: Restore archived build
+        uses: actions/download-artifact@v4
+        with:
+          path: build-temp
+      - name: Display structure of build
+        run: ls -R build
+      # - run: yarn test --build ${{ matrix.test_params }} --ci=github
+
diff --git a/packages/react-devtools-shared/src/__tests__/storeStressTestConcurrent-test.js b/packages/react-devtools-shared/src/__tests__/storeStressTestConcurrent-test.js
index 472ad31671a76..8dd4ce428438f 100644
--- a/packages/react-devtools-shared/src/__tests__/storeStressTestConcurrent-test.js
+++ b/packages/react-devtools-shared/src/__tests__/storeStressTestConcurrent-test.js
@@ -16,6 +16,8 @@ describe('StoreStressConcurrent', () => {
   let store;
   let print;
 
+  jest.setTimeout(15000);
+
   beforeEach(() => {
     global.IS_REACT_ACT_ENVIRONMENT = true;
 
diff --git a/packages/shared/ReactVersion.js b/packages/shared/ReactVersion.js
index 13dd40e747e0d..c215912df2204 100644
--- a/packages/shared/ReactVersion.js
+++ b/packages/shared/ReactVersion.js
@@ -1,15 +1 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-// TODO: this is special because it gets imported during build.
-//
-// It exists as a placeholder so that DevTools can support work tag changes between releases.
-// When we next publish a release, update the matching TODO in backend/renderer.js
-// TODO: This module is used both by the release scripts and to expose a version
-// at runtime. We should instead inject the version number as part of the build
-// process, and use the ReactVersions.js module as the single source of truth.
-export default '19.0.0';
+export default '19.0.0-rc-3a600d54b3-20240624';
diff --git a/scripts/rollup/build-ghaction.js b/scripts/rollup/build-ghaction.js
index 60871e3e9208c..ce2ee7addb878 100644
--- a/scripts/rollup/build-ghaction.js
+++ b/scripts/rollup/build-ghaction.js
@@ -846,9 +846,7 @@ async function buildEverything(bundleTypeToBuild) {
   );
 
   await Promise.all(
-    bundles.map(([bundle, bundleType]) => {
-      return createBundle(bundle, bundleType);
-    })
+    bundles.map(([bundle, bundleType]) => createBundle(bundle, bundleType))
   );
 
   await Packaging.copyAllShims();