diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 86ae739ae..96b48891a 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -55,11 +55,6 @@ jobs:
               python3 -m pip wheel . --wheel-dir /src/dist
             '
 
-      - uses: actions/upload-artifact@v4
-        with:
-          name: linux-musl-wheel
-          path: dist/*.whl
-
   build-manylinux-wheel:
     runs-on: ubuntu-latest
     name: Build Linux amd64 wheel (manylinux2014, glibc 2.17+)
@@ -121,11 +116,6 @@ jobs:
               done
             '
 
-      - uses: actions/upload-artifact@v4
-        with:
-          name: linux-manylinux-wheel
-          path: dist-manylinux/*.whl
-
   build-macos-wheel:
     runs-on: macos-15
     name: Build macOS arm64 wheel
@@ -162,11 +152,6 @@ jobs:
           mkdir -p dist
           python3 -m pip wheel . --wheel-dir dist
 
-      - uses: actions/upload-artifact@v4
-        with:
-          name: macos-wheel
-          path: dist/*.whl
-
   release:
     # allow testing outside main branch
     if: github.ref_name == 'main'
diff --git a/.github/workflows/test-build.yml b/.github/workflows/test-build.yml
index 56e94328e..01a7e505c 100644
--- a/.github/workflows/test-build.yml
+++ b/.github/workflows/test-build.yml
@@ -90,7 +90,13 @@ jobs:
           key: test-build-${{ matrix.os }}
           save: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
           restore-keys: |
-            test-build-${{ matrix.os }}-
+            test-build-${{ matrix.os }}
+
+      - name: Cache Build Directory
+        uses: actions/cache@v6
+        with:
+          path: build
+          key: ${{ runner.os }}-build-${{ github.run_id }}
 
       - name: Build
         shell: bash
@@ -104,19 +110,6 @@ jobs:
         run: |
           ./build/yosys-config || true
 
-      - name: Compress build
-        shell: bash
-        run: |
-          cd build
-          tar -cvf ../build.tar share/ yosys yosys-*
-
-      - name: Store build artifact
-        uses: actions/upload-artifact@v7
-        with:
-          name: build-${{ matrix.os }}
-          path: build.tar
-          retention-days: 1
-
   test-yosys:
     name: Run tests
     runs-on: ${{ matrix.os }}
@@ -142,16 +135,12 @@ jobs:
           get-build-deps: true
           get-iverilog: true
 
-      - name: Download build artifact
-        uses: actions/download-artifact@v8
+      - name: Restore Build Directory from Cache
+        uses: actions/cache@v6
         with:
-          name: build-${{ matrix.os }}
-
-      - name: Uncompress build
-        shell: bash
-        run: |
-          mkdir -p build
-          tar -xvf build.tar -C build
+          path: build
+          key: ${{ runner.os }}-build-${{ github.run_id }}
+          fail-on-cache-miss: true
 
       - name: Log yosys-config output
         run: |
@@ -192,19 +181,17 @@ jobs:
         with:
           runs-on: ${{ matrix.os }}
 
-      - name: Download build artifact
-        uses: actions/download-artifact@v8
+      - name: Restore Build Directory from Cache
+        uses: actions/cache@v6
         with:
-          name: build-${{ matrix.os }}
-
-      - name: Uncompress build
-        shell: bash
-        run:
-          tar -xvf build.tar
+          path: build
+          key: ${{ runner.os }}-build-${{ github.run_id }}
+          fail-on-cache-miss: true
 
       - name: test_cell
         shell: bash
         run: |
+          cd build
           ./yosys -p 'test_cell -n 20 -s 1 all'
           ./yosys -p 'test_cell -n 20 -s 1 -nosat -aigmap $pow $pmux'
           ./yosys -p 'test_cell -n 20 -s 1 -nosat -aigmap $eqx $nex $bweqx'
@@ -233,16 +220,12 @@ jobs:
           get-build-deps: true
           get-docs-deps: true
 
-      - name: Download build artifact
-        uses: actions/download-artifact@v8
+      - name: Restore Build Directory from Cache
+        uses: actions/cache@v6
         with:
-          name: build-${{ matrix.os }}
-
-      - name: Uncompress build
-        shell: bash
-        run: |
-          mkdir -p build
-          tar -xvf build.tar -C build
+          path: build
+          key: ${{ runner.os }}-build-${{ github.run_id }}
+          fail-on-cache-miss: true
 
       - name: Log yosys-config output
         run: |