diff --git a/.github/workflows/backend-ci.yml b/.github/workflows/backend-ci.yml
index d11f4959..f731bc25 100644
--- a/.github/workflows/backend-ci.yml
+++ b/.github/workflows/backend-ci.yml
@@ -11,28 +11,46 @@ on:
         - chartlets.py/**
       
 jobs:
-  backend:
-      runs-on: ubuntu-latest
-      steps:
-        - name: git-checkout chartlets
-          uses: actions/checkout@v4
-          
-        - name: Set up Micromamba
-          uses: mamba-org/setup-micromamba@v1
-          with:
-            environment-file: chartlets.py/environment.yml
-            
-        - name: Run unit tests
-          shell: bash -l {0}
-          run: |
-            cd chartlets.py 
-            pytest --cov=chartlets --cov-report=xml
+  python-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
+    defaults:
+      run:
+        working-directory: chartlets.py 
 
-        - name: Upload coverage reports to Codecov
-          uses: codecov/codecov-action@v4
-          with:
-            fail_ci_if_error: true
-            directory: chartlets.py/
-            flags: backend
-            verbose: true
-            token: ${{ secrets.CODECOV_TOKEN }}
+    steps:
+    - uses: actions/checkout@v3
+    
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python-version }}
+        
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install .[dev,demo]
+        
+    - name: Lint with flake8
+      run: |
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+        
+    - name: Run unit tests
+      shell: bash -l {0}
+      run: |
+        pytest --cov=chartlets --cov-report=xml
+
+    - name: Upload coverage reports to Codecov
+      uses: codecov/codecov-action@v4
+      with:
+        fail_ci_if_error: true
+        directory: chartlets.py/
+        flags: backend
+        verbose: true
+        token: ${{ secrets.CODECOV_TOKEN }}
diff --git a/.github/workflows/frontend-ci.yml b/.github/workflows/frontend-ci.yml
index 1d46c376..7bac187d 100644
--- a/.github/workflows/frontend-ci.yml
+++ b/.github/workflows/frontend-ci.yml
@@ -10,58 +10,63 @@ on:
     paths:
         - chartlets.js/**
 
-jobs:       
-  frontend:
-    runs-on: ubuntu-latest
-    steps:
-      - name: git-checkout chartlets
-        uses: actions/checkout@v4
-
-      - name: Set up Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: '18.x'
-
-      - name: Install common dependencies
-        run: |
-          cd chartlets.js 
-          npm install 
-
-      - name: Lib lint
-        run: |
-          cd chartlets.js/packages/lib  
-          npm run lint
-
-      - name: Lib tests
-        run: |
-          cd chartlets.js/packages/lib  
-          npm run test
-
-      - name: Lib coverage
-        run: |
-          cd chartlets.js/packages/lib  
-          npm run coverage
-
-      - name: Upload coverage reports for lib to Codecov
-        uses: codecov/codecov-action@v4
-        with:
-          fail_ci_if_error: true
-          directory: chartlets.js/packages/lib/coverage/
-          flags: frontend
-          verbose: true
-          token: ${{ secrets.CODECOV_TOKEN }}
-
-      - name: Lib build
-        run: |
-          cd chartlets.js/packages/lib  
-          npm run build
-
-      - name: Demo lint
-        run: |
-          cd chartlets.js/packages/demo  
-          npm run lint
-
-      - name: Demo build
-        run: |
-          cd chartlets.js/packages/demo  
-          npm run build
+jobs:    
+  npm-tests-lib:
+      runs-on: ubuntu-latest
+      strategy:
+        matrix:
+          node-version: [16.x, 18.x, 20.x]
+          # See supported Node.js release schedule at
+          # https://nodejs.org/en/about/releases/
+      defaults:
+        run:
+          working-directory: chartlets.js/packages/lib
+  
+      steps:
+        - uses: actions/checkout@v3
+        - name: Use Node.js ${{ matrix.node-version }}
+          uses: actions/setup-node@v3
+          with:
+            node-version: ${{ matrix.node-version }}
+            cache: 'npm'
+            cache-dependency-path: chartlets.js/package-lock.json
+            
+        - run: npm ci
+        - run: npm run lint
+        - run: npm run test
+        
+        - run: npm run coverage
+        - name: Upload coverage reports for lib to Codecov
+          uses: codecov/codecov-action@v4
+          with:
+            fail_ci_if_error: true
+            directory: coverage/
+            flags: frontend
+            verbose: true
+            token: ${{ secrets.CODECOV_TOKEN }}
+            
+        - run: npm run build
+      
+  npm-tests-demo:
+      runs-on: ubuntu-latest
+      strategy:
+        matrix:
+          node-version: [16.x, 18.x, 20.x]
+          # See supported Node.js release schedule at
+          # https://nodejs.org/en/about/releases/
+      defaults:
+        run:
+          working-directory: chartlets.js/packages/demo
+  
+      steps:
+        - uses: actions/checkout@v3
+        - name: Use Node.js ${{ matrix.node-version }}
+          uses: actions/setup-node@v3
+          with:
+            node-version: ${{ matrix.node-version }}
+            cache: 'npm'
+            cache-dependency-path: chartlets.js/package-lock.json
+            
+        - run: npm ci
+        - run: npm run lint
+        - run: npm run build
diff --git a/.github/workflows/publish-backend.yml b/.github/workflows/publish-backend.yml
index 4877d38d..f1491114 100644
--- a/.github/workflows/publish-backend.yml
+++ b/.github/workflows/publish-backend.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
     defaults:
       run:
         working-directory: chartlets.py