diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
new file mode 100644
index 00000000..7ecba5cb
--- /dev/null
+++ b/.github/workflows/format.yml
@@ -0,0 +1,17 @@
+name: format
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  format:
+    name: format
+    runs-on: 'ubuntu-latest'
+    container: ghcr.io/c-cube/c-cube-commmon/ci-doc-5.3:latest
+    steps:
+      - uses: actions/checkout@v6
+      - run: opam exec -- make format-check
+
diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index f022b4ca..f08a39ca 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -9,20 +9,14 @@ jobs:
   deploy:
     name: Deploy doc
     runs-on: ubuntu-latest
+    container: ghcr.io/c-cube/c-cube-commmon/ci-doc-5.3:latest
     steps:
-      - uses: actions/checkout@main
-
-      - name: Use OCaml
-        uses: ocaml/setup-ocaml@v3
-        with:
-          ocaml-compiler: '5.3'
-          dune-cache: true
-          allow-prerelease-opam: true
+      - uses: actions/checkout@v6
 
       # temporary until it's in a release
       - run: opam pin picos 0.6.0 -y -n
 
-      - run: opam install odig moonpool moonpool-lwt -t
+      - run: opam install moonpool moonpool-lwt -t
 
       - run: opam exec -- odig odoc --cache-dir=_doc/ moonpool moonpool-lwt
 
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a54303e8..24222352 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,4 +1,4 @@
-name: Build and Test
+name: build
 
 on:
   push:
@@ -13,22 +13,14 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        os:
-            - ubuntu-latest
-        ocaml-compiler:
-            - '5.0'
-            - '5.3'
+        container:
+          - ghcr.io/c-cube/c-cube-commmon/ci-5.0:latest
+          - ghcr.io/c-cube/c-cube-commmon/ci-5.4:latest
 
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
+    container: ${{ matrix.container }}
     steps:
-      - uses: actions/checkout@main
-      - name: Use OCaml ${{ matrix.ocaml-compiler }}
-        uses: ocaml/setup-ocaml@v3
-        with:
-          ocaml-compiler: ${{ matrix.ocaml-compiler }}
-          dune-cache: true
-          allow-prerelease-opam: true
-
+      - uses: actions/checkout@v6
       - run: opam pin picos 0.6.0 -y -n
 
       - run: opam install -t . --deps-only
@@ -40,6 +32,7 @@ jobs:
 
   compat:
     name: build-compat # compat with other OSes
+    needs: run  # only run this if cheap linux job passed
     timeout-minutes: 15
     strategy:
       fail-fast: true
@@ -67,23 +60,3 @@ jobs:
       # install some depopts
       - run: opam install thread-local-storage trace domain-local-await
       - run: opam exec -- dune build --profile=release --force @install @runtest
-
-  format:
-    name: format
-    strategy:
-      matrix:
-        ocaml-compiler:
-            - '5.3'
-    runs-on: 'ubuntu-latest'
-    steps:
-      - uses: actions/checkout@main
-      - name: Use OCaml ${{ matrix.ocaml-compiler }}
-        uses: ocaml/setup-ocaml@v3
-        with:
-          ocaml-compiler: ${{ matrix.ocaml-compiler }}
-          dune-cache: true
-          allow-prerelease-opam: true
-
-      - run: opam install ocamlformat.0.27.0
-      - run: opam exec -- make format-check
-