diff --git a/.github/workflows/ci.yml b/.github/workflows/ci-linux.yml
similarity index 77%
rename from .github/workflows/ci.yml
rename to .github/workflows/ci-linux.yml
index 93a77966e..a877d3bff 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci-linux.yml
@@ -9,79 +9,44 @@ on:
     branches:
       - main
 
-  schedule:
-      # At minute 0 past every 2nd hour. (see https://crontab.guru)
-      # this job is to keep the ccache cache warm
-      # specifically for the free windows runner
-    - cron: '0 */2 * * *'
-
 concurrency:
   # A PR number if a pull request and otherwise the commit hash. This cancels
   # queued and in-progress runs for the same PR (presubmit) or commit
   # (postsubmit).
-  group: ci-build-test-${{ github.event.number || github.sha }}
+  group: ci-build-test-cpp-linux-${{ github.event.number || github.sha }}
   cancel-in-progress: true
 
-defaults:
-  run:
-    # force bash for windows
-    shell: bash
-
 jobs:
   build_and_ctest:
-    name: Build and Test (${{ matrix.os }}, ASSERTIONS)
-    runs-on: ${{ matrix.runs-on }}
+    name: Build and Test (linux, ASSERTIONS)
+    runs-on: nod-ai-shared-cpubuilder-manylinux-x86_64
     strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - os: linux
-            runs-on: nod-ai-shared-cpubuilder-manylinux-x86_64
-          - os: windows
-            runs-on: windows-2019
+      fail-fast: true
     env:
       CACHE_DIR: ${{ github.workspace }}/.container-cache
     steps:
       - name: Set unified TZ
         uses: szenius/set-timezone@v2.0
         with:
+          # this is an arbitrary choice
           timezoneLinux: "Asia/Singapore"
           timezoneMacos: "Asia/Singapore"
           timezoneWindows: "Singapore Standard Time"
-          
+
       - name: Configure local git mirrors
-        if: ${{ matrix.runs-on == 'nod-ai-shared-cpubuilder-manylinux-x86_64' }}
         run: |
           /gitmirror/scripts/trigger_update_mirrors.sh
           /gitmirror/scripts/git_config.sh
-
       - name: "Checking out repository"
         uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3 # v3.5.0
         with:
           submodules: recursive
 
       - name: Install static libs
-        if: ${{ matrix.runs-on == 'nod-ai-shared-cpubuilder-manylinux-x86_64' }}
         run: |
           dnf install -y almalinux-release-devel
           yum remove -y openssl-devel zlib-devel || true
           yum install -y protobuf-devel protobuf-compiler
-
-      - name: Setup Cpp
-        uses: aminya/setup-cpp@v1
-        if: ${{ matrix.os == 'windows' }}
-        with:
-          compiler: msvc
-          vcvarsall: true
-          cmake: true
-          ninja: true
-          ccache: true
-
-      - uses: actions/setup-python@v4
-        if: ${{ matrix.os == 'windows' }}
-        with:
-          python-version: '3.11'
-
       - name: Sync source deps
         run: |
           python ./sync_deps.py
@@ -94,9 +59,8 @@ jobs:
         uses: actions/cache/restore@v3
         with:
           path: ${{ env.CACHE_DIR }}
-          # without this you'll get collisions ("Failed to save: Unable to reserve cache with key ..., another job may be creating this cache.")
-          key: "${{ matrix.os }}-build-test-cpp-asserts-v1-${{ github.sha }}-${{ github.event.repository.updated_at }}"
-          restore-keys: "${{ matrix.os }}-build-test-cpp-"
+          key: linux-build-test-cpp-asserts-manylinux-v2-${{ github.sha }}
+          restore-keys: linux-build-test-cpp-
 
       - name: Build packages
         run: |
@@ -108,14 +72,14 @@ jobs:
         run: |
           rm -f iree-install/bin/clang*
           rm -f iree-install/bin/llvm-link*
-          tar cf iree-${{ matrix.os }}-dist.tar -C iree-install . -C ../iree-build tools/testing/e2e/iree-e2e-matmul-test
+          tar cf iree-dist-linux.tar -C iree-install . -C ../iree-build tools/testing/e2e/iree-e2e-matmul-test
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v4
         if: ${{ !cancelled() }}
         with:
-          name: "${{ matrix.os }}_x86_64_release_packages"
-          path: "iree-${{ matrix.os }}-dist.tar"
+          name: linux_x86_64_release_packages
+          path: iree-dist-linux.tar
           if-no-files-found: warn
 
       - name: Save cache
@@ -123,7 +87,7 @@ jobs:
         if: ${{ !cancelled() }}
         with:
           path: ${{ env.CACHE_DIR }}
-          key: "${{ matrix.os }}-build-test-cpp-asserts-v1-${{ github.sha }}-${{ github.event.repository.updated_at }}"
+          key: linux-build-test-cpp-asserts-manylinux-v2-${{ github.sha }}
 
   test_linux:
     name: E2E Test linux
@@ -147,7 +111,7 @@ jobs:
       - name: Extract artifact
         run: |
           mkdir iree-install
-          tar -xf iree-linux-dist.tar -C iree-install
+          tar -xf iree-dist-linux.tar -C iree-install
           bash build_tools/download_peano.sh
 
       - name: Create venv and install dependencies
diff --git a/.github/workflows/ci-windows.yml b/.github/workflows/ci-windows.yml
new file mode 100644
index 000000000..2f27257e1
--- /dev/null
+++ b/.github/workflows/ci-windows.yml
@@ -0,0 +1,106 @@
+name: CI
+
+on:
+  workflow_call:
+  workflow_dispatch:
+  pull_request:
+  merge_group:
+  push:
+    branches:
+      - main
+
+  schedule:
+      # At minute 0 past every 4nd hour. (see https://crontab.guru)
+      # this job is to keep the ccache cache warm
+    - cron: '0 */4 * * *'
+
+concurrency:
+  # A PR number if a pull request and otherwise the commit hash. This cancels
+  # queued and in-progress runs for the same PR (presubmit) or commit
+  # (postsubmit).
+  group: ci-build-test-cpp-windows-${{ github.event.number || github.sha }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    # force bash for windows
+    shell: bash
+
+jobs:
+  build_and_ctest:
+    name: Build and Test (windows, ASSERTIONS)
+    runs-on: windows-2019
+    strategy:
+      fail-fast: true
+    env:
+      CACHE_DIR: ${{ github.workspace }}/.container-cache
+    steps:
+      - name: Set unified TZ
+        uses: szenius/set-timezone@v2.0
+        with:
+          # this is an arbitrary choice
+          timezoneLinux: "Asia/Singapore"
+          timezoneMacos: "Asia/Singapore"
+          timezoneWindows: "Singapore Standard Time"
+          
+      - name: "Checking out repository"
+        uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3 # v3.5.0
+        with:
+          submodules: recursive
+
+      - name: Setup Cpp
+        uses: aminya/setup-cpp@v1
+        with:
+          compiler: msvc
+          vcvarsall: true
+          cmake: true
+          ninja: true
+          ccache: true
+
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+
+      - name: Sync source deps
+        run: |
+          python ./sync_deps.py
+
+      - name: Python deps
+        run: |
+          pip install "numpy<2" pyyaml "pybind11[global]==2.10.3" nanobind
+
+      - name: Enable cache
+        uses: actions/cache/restore@v3
+        with:
+          path: ${{ env.CACHE_DIR }}
+          # without datetime stamps you'll get collisions for the cache warming runs
+          # ("Failed to save: Unable to reserve cache with key ..., another job may be creating this cache.")
+          key: windows-build-test-cpp-asserts-v1-${{ github.sha }}-${{ github.event.repository.updated_at }}
+          restore-keys: windows-build-test-cpp-
+
+      - name: Build packages
+        run: |
+          export cache_dir="${{ env.CACHE_DIR }}"
+          bash build_tools/ci/build_test_cpp.sh
+
+      - name: Create artifacts
+        if: ${{ !cancelled() }}
+        run: |
+          rm -f iree-install/bin/clang*
+          rm -f iree-install/bin/llvm-link*
+          tar cf iree-dist-windows.tar -C iree-install . -C ../iree-build tools/testing/e2e/iree-e2e-matmul-test.exe
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        if: ${{ !cancelled() }}
+        with:
+          name: windows_x86_64_release_packages
+          path: iree-dist-windows.tar
+          if-no-files-found: warn
+
+      - name: Save cache
+        uses: actions/cache/save@v3
+        if: ${{ !cancelled() }}
+        with:
+          path: ${{ env.CACHE_DIR }}
+          key: windows-build-test-cpp-asserts-v1-${{ github.sha }}-${{ github.event.repository.updated_at }}