diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 82e4a6aaf82eb4d..ef5a7b23435aa1d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -89,11 +89,9 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: npx tsx bin/post-pr-ci-failure-comment/index.ts
 
-  build:
-    name: Build
+  pre-build:
+    name: Pre Build
     runs-on: ubuntu-latest
-    outputs:
-      link_check_failed: ${{ steps.check_link_result.outputs.failed }}
     permissions:
       contents: read
       pull-requests: write
@@ -114,7 +112,8 @@ jobs:
             exit 1
           fi
 
-      - run: |
+      - name: Check for invalid file extensions
+        run: |
           FILES=$(
             find src/content \
               -type f \
@@ -132,27 +131,17 @@ jobs:
             exit 1
           fi
 
-      - name: Cache node_modules
+      - name: Restore node_modules (cache hit)
         id: node-modules-cache
         uses: actions/cache@v5
         with:
           path: node_modules
           key: node-modules-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
 
-      - name: Run sync (if cache hit)
-        run: npm run sync
-        if: steps.node-modules-cache.outputs.cache-hit == 'true'
-
-      - name: Node install (cache miss)
+      - name: Install node_modules (cache miss)
         run: npm ci
         if: steps.node-modules-cache.outputs.cache-hit != 'true'
 
-      - uses: actions/cache/restore@v5
-        with:
-          path: |
-            node_modules/.astro/assets
-          key: static
-
       - run: npx tsx bin/post-codeowners-comment/index.ts
         continue-on-error: true
         env:
@@ -160,10 +149,64 @@ jobs:
 
       - run: npm run check
 
+      - run: npm run check:worker
+
+      - uses: reviewdog/action-eslint@v1
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          reporter: github-pr-review
+          fail_level: error
+          filter_mode: nofilter
+
+      - run: npm run format:core:check
+
+      - name: Validate redirects
+        run: npx tsm bin/validate-redirects.ts
+
+      - name: Tests
+        run: npm run test:prebuild
+
+  build:
+    name: Build
+    needs: pre-build
+    runs-on: ubuntu-latest
+    outputs:
+      link_check_failed: ${{ steps.check_link_result.outputs.failed }}
+    permissions:
+      contents: read
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 1
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: 22.x
+          cache: npm
+
+      - name: Restore node_modules (cache hit)
+        id: node-modules-cache
+        uses: actions/cache@v5
+        with:
+          path: node_modules
+          key: node-modules-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
+
+      - name: Install node_modules (cache miss)
+        run: npm ci
+        if: steps.node-modules-cache.outputs.cache-hit != 'true'
+
+      - name: Restore Astro assets from cache
+        uses: actions/cache@v5
+        with:
+          path: |
+            node_modules/.astro/assets
+          key: static
+
       # The starlight-links-validator plugin runs in astro:build:done, which fires
       # AFTER all pages have been written to dist/. If link validation fails, the
       # build exits non-zero but dist/ is complete. We use continue-on-error so the
-      # job succeeds (allowing deploy + validate to run), then check the outcome below.
+      # job succeeds (allowing deploy + post-build to run), then check the outcome below.
       - run: npm run build
         id: build_step
         name: Build
@@ -188,19 +231,13 @@ jobs:
             echo "failed=false" >> "$GITHUB_OUTPUT"
           fi
 
-      - uses: actions/cache/save@v5
-        with:
-          path: |
-            node_modules/.astro/assets
-          key: static
-
       - uses: actions/upload-artifact@v7
         with:
           name: dist
           path: dist
 
-  validate:
-    name: Validate
+  post-build:
+    name: Post Build
     needs: build
     runs-on: ubuntu-latest
     permissions:
@@ -216,27 +253,24 @@ jobs:
           node-version: 22.x
           cache: npm
 
-      - run: npm ci
+      - name: Restore node_modules (cache hit)
+        id: node-modules-cache
+        uses: actions/cache@v5
+        with:
+          path: node_modules
+          key: node-modules-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
+
+      - name: Install node_modules (cache miss)
+        run: npm ci
+        if: steps.node-modules-cache.outputs.cache-hit != 'true'
 
       - uses: actions/download-artifact@v8
         with:
           name: dist
           path: dist
 
-      - uses: reviewdog/action-eslint@v1
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          reporter: github-pr-review
-          fail_level: error
-          filter_mode: nofilter
-
-      - run: npm run format:core:check
-
-      - name: Validate redirects
-        run: npx tsm bin/validate-redirects.ts
-
-      - name: Tests
-        run: npm run test
+      - name: Tests (Workers)
+        run: npm run test:postbuild
 
       - name: Link validation
         if: needs.build.outputs.link_check_failed == 'true'
@@ -246,7 +280,7 @@ jobs:
 
   notify:
     name: Notify
-    needs: [build, validate]
+    needs: [pre-build, build, post-build]
     if: always()
     runs-on: ubuntu-latest
     permissions:
@@ -262,7 +296,16 @@ jobs:
           node-version: 22.x
           cache: npm
 
-      - run: npm ci
+      - name: Restore node_modules (cache hit)
+        id: node-modules-cache
+        uses: actions/cache@v5
+        with:
+          path: node_modules
+          key: node-modules-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
+
+      - name: Install node_modules (cache miss)
+        run: npm ci
+        if: steps.node-modules-cache.outputs.cache-hit != 'true'
 
       - name: Post PR CI failure comment
         continue-on-error: true
@@ -288,7 +331,16 @@ jobs:
           node-version: 22.x
           cache: npm
 
-      - run: npm ci
+      - name: Restore node_modules (cache hit)
+        id: node-modules-cache
+        uses: actions/cache@v5
+        with:
+          path: node_modules
+          key: node-modules-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
+
+      - name: Install node_modules (cache miss)
+        run: npm ci
+        if: steps.node-modules-cache.outputs.cache-hit != 'true'
 
       - uses: actions/download-artifact@v8
         with:
diff --git a/bin/post-pr-ci-failure-comment/index.ts b/bin/post-pr-ci-failure-comment/index.ts
index 3f168bde4a03638..0afca2394e59fac 100644
--- a/bin/post-pr-ci-failure-comment/index.ts
+++ b/bin/post-pr-ci-failure-comment/index.ts
@@ -25,11 +25,14 @@ async function run(): Promise<void> {
 		});
 
 		const ciJobs = run.jobs.filter(
-			(job) => job.name === "Build" || job.name === "Validate",
+			(job) =>
+				job.name === "Pre Build" ||
+				job.name === "Build" ||
+				job.name === "Post Build",
 		);
 
 		if (ciJobs.length === 0) {
-			core.setFailed(`Could not find Build or Validate jobs`);
+			core.setFailed(`Could not find Pre Build, Build, or Post Build jobs`);
 			process.exit();
 		}
 
diff --git a/package.json b/package.json
index df570841140c3b0..eb0b981129666d8 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,8 @@
 		"start": "npx astro dev",
 		"sync": "npx astro sync",
 		"test": "npx vitest",
+		"test:prebuild": "npx vitest --project Node --project Astro",
+		"test:postbuild": "npx vitest --project Workers",
 		"lint": "npx eslint",
 		"ai-setup:import-from-opencode": "npx rulesync import --targets opencode --features rules,commands,subagents",
 		"ai-setup:claudecode": "npm run ai-setup:import-from-opencode && npx rulesync generate --targets claudecode --features rules,commands,subagents",