diff --git a/.github/workflows/jit.yml b/.github/workflows/jit.yml
index cb60debe79cb7e..9fa8934166c3ec 100644
--- a/.github/workflows/jit.yml
+++ b/.github/workflows/jit.yml
@@ -31,6 +31,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+env:
+  LLVM: 19
+
 jobs:
   interpreter:
     name: Interpreter (Debug)
@@ -45,49 +48,22 @@ jobs:
       - name: Test tier two interpreter
         run: |
           ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
-  jit:
-    name: ${{ matrix.target }} (${{ matrix.debug && 'Debug' || 'Release' }})
+
+  jit-windows:
+    name: Windows (${{ matrix.arch }}, ${{ matrix.debug && 'Debug' || 'Release' }})
     needs: interpreter
-    runs-on: ${{ matrix.runner }}
+    runs-on: windows-latest
     timeout-minutes: 90
     strategy:
       fail-fast: false
       matrix:
-        target:
-          - i686-pc-windows-msvc/msvc
-          - x86_64-pc-windows-msvc/msvc
-          - aarch64-pc-windows-msvc/msvc
-          - x86_64-apple-darwin/clang
-          - aarch64-apple-darwin/clang
-          - x86_64-unknown-linux-gnu/gcc
-          - aarch64-unknown-linux-gnu/gcc
+        arch:
+          - x64
+          - Win32
+          - ARM64
         debug:
           - true
           - false
-        llvm:
-          - 19
-        include:
-          - target: i686-pc-windows-msvc/msvc
-            architecture: Win32
-            runner: windows-latest
-          - target: x86_64-pc-windows-msvc/msvc
-            architecture: x64
-            runner: windows-latest
-          - target: aarch64-pc-windows-msvc/msvc
-            architecture: ARM64
-            runner: windows-latest
-          - target: x86_64-apple-darwin/clang
-            architecture: x86_64
-            runner: macos-13
-          - target: aarch64-apple-darwin/clang
-            architecture: aarch64
-            runner: macos-14
-          - target: x86_64-unknown-linux-gnu/gcc
-            architecture: x86_64
-            runner: ubuntu-24.04
-          - target: aarch64-unknown-linux-gnu/gcc
-            architecture: aarch64
-            runner: ubuntu-24.04-aarch64
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -95,39 +71,82 @@ jobs:
           python-version: '3.11'
 
       - name: Native Windows
-        if: runner.os == 'Windows' && matrix.architecture != 'ARM64'
+        if: matrix.arch != 'ARM64'
         run: |
-          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
-          ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.architecture }}
-          ./PCbuild/rt.bat ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
+          choco install llvm --allow-downgrade --no-progress --version ${{ env.LLVM }}.1.0
+          ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.arch }}
+          ./PCbuild/rt.bat ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.arch }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
       # No tests (yet):
       - name: Emulated Windows
-        if: runner.os == 'Windows' && matrix.architecture == 'ARM64'
+        if: matrix.arch == 'ARM64'
         run: |
-          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
-          ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.architecture }}
+          choco install llvm --allow-downgrade --no-progress --version ${{ env.LLVM }}.1.0
+          ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '' }} -p ${{ matrix.arch }}
 
+  jit-mac:
+    name: macOS (${{ matrix.os }}, ${{ matrix.debug && 'Debug' || 'Release' }})
+    needs: interpreter
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 90
+    strategy:
+      fail-fast: false
+      matrix:
+        # macos-14 are M1, macos-13 are default GHA Intel.
+        os:
+        - macos-14
+        - macos-13
+        debug:
+          - true
+          - false
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
         # The `find` line is required as a result of https://github.com/actions/runner-images/issues/9966.
         # This is a bug in the macOS runner image where the pre-installed Python is installed in the same
         # directory as the Homebrew Python, which causes the build to fail for macos-13. This line removes
         # the symlink to the pre-installed Python so that the Homebrew Python is used instead.
-      - name: Native macOS
-        if: runner.os == 'macOS'
+      - name: ${{ runner.os }} (${{ runner.arch }})
         run: |
           brew update
           find /usr/local/bin -lname '*/Library/Frameworks/Python.framework/*' -delete
-          brew install llvm@${{ matrix.llvm }}
+          brew install llvm@${{ env.LLVM }}
           export SDKROOT="$(xcrun --show-sdk-path)"
           ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '' }}
           make all --jobs 4
           ./python.exe -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
-      - name: Native Linux
-        if: runner.os == 'Linux'
+  jit-ubuntu:
+    name: Ubuntu (${{ matrix.os }}, ${{ matrix.debug && 'Debug' || 'Release' }})
+    needs: interpreter
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 90
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+        - ubuntu-24.04
+        - ubuntu-24.04-aarch64
+        debug:
+          - true
+          - false
+        is-fork:  # only used for the exclusion trick
+        - ${{ github.repository_owner != 'python' }}
+        exclude:
+        - os: ubuntu-24.04-aarch64
+          is-fork: true
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: ${{ runner.os }} (${{ runner.arch }})
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
-          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
+          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM }}
+          export PATH="$(llvm-config-${{ env.llvm }} --bindir):$PATH"
           ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '' }}
           make all --jobs 4
           ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
@@ -136,10 +155,6 @@ jobs:
     name: Free-Threaded (Debug)
     needs: interpreter
     runs-on: ubuntu-24.04
-    strategy:
-      matrix:
-        llvm:
-          - 19
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -147,8 +162,8 @@ jobs:
           python-version: '3.11'
       - name: Build with JIT enabled and GIL disabled
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
-          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
+          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM }}
+          export PATH="$(llvm-config-${{ env.llvm }} --bindir):$PATH"
           ./configure --enable-experimental-jit --with-pydebug --disable-gil
           make all --jobs 4
       - name: Run tests