diff --git a/.github/workflows/production-deploy.yml b/.github/workflows/production-deploy.yml
index 92570dd..012eb0c 100644
--- a/.github/workflows/production-deploy.yml
+++ b/.github/workflows/production-deploy.yml
@@ -42,7 +42,7 @@ jobs:
       environment: "production"
       version-bump: ${{ inputs.version-bump }}
       branch: ${{ inputs.branch }}
-      run-database-tests: false
+      run-database-tests: true
       seed: ${{ inputs.seed }}
       request_delay: ${{ inputs.request_delay }}
       max_concurrency: ${{ inputs.max_concurrency }}
diff --git a/.github/workflows/staging-deploy.yml b/.github/workflows/staging-deploy.yml
index 5e12dc2..4a8443b 100644
--- a/.github/workflows/staging-deploy.yml
+++ b/.github/workflows/staging-deploy.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8"]
+        python-version: ["3.12"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4
diff --git a/.github/workflows/test-lint.yml b/.github/workflows/test-lint.yml
new file mode 100644
index 0000000..0f1e91d
--- /dev/null
+++ b/.github/workflows/test-lint.yml
@@ -0,0 +1,55 @@
+name: Test and Lint
+
+on:
+  pull_request:
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      actions: read
+      checks: write
+      pull-requests: write
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.12"]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        id: python-setup
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: |
+          python -m venv .venv
+          .venv/bin/pip install pytest
+          .venv/bin/pip install -r app/requirements.txt
+
+      - name: Lint with flake8
+        run: |
+          source .venv/bin/activate
+          .venv/bin/pip install flake8
+          # stop the build if there are Python syntax errors or undefined names
+          flake8 ./app --count --select=E9,F63,F7,F82 --show-source --statistics
+          # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+          flake8 ./app --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+
+      - name: Run tests
+        if: always()
+        run: |
+          source .venv/bin/activate
+          pytest --junit-xml=./reports/pytest.xml --tb=auto -v
+
+      - name: Upload test results
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: test-results-${{ matrix.python-version }}
+          path: ./reports/pytest.xml
+          if-no-files-found: warn
\ No newline at end of file
diff --git a/README.md b/README.md
index ac8bc9b..6d49acf 100755
--- a/README.md
+++ b/README.md
@@ -19,9 +19,9 @@ This evaluation function compares physical quantities submitted by students agai
 app/
     __init__.py
     evaluation.py              # Main evaluation function
-    evaluation_test.py         # Unit tests
+    evaluation_tests.py        # Unit tests
     preview.py                 # Preview function
-    preview_test.py            # Preview tests
+    preview_tests.py           # Preview tests
     expression_utilities.py    # Expression parsing utilities
     unit_system_conversions.py # Unit conversion logic
     static_unit_conversion_arrays.py  # Pre-generated conversion data
diff --git a/app/Dockerfile b/app/Dockerfile
index c32d85a..0291cfe 100755
--- a/app/Dockerfile
+++ b/app/Dockerfile
@@ -1,22 +1,28 @@
-# Base image that bundles AWS Lambda Python 3.8 image with some middleware functions
-# FROM base-eval-tmp
-FROM ghcr.io/lambda-feedback/baseevalutionfunctionlayer:main-3.8
+# Base image that bundles the AWS Lambda Python image with the lambda-feedback middleware (app.handler)
+FROM ghcr.io/lambda-feedback/baseevalutionfunctionlayer:main-3.12
+
+# The 3.12 image is Amazon Linux 2023, which doesn't ship `find` (used below).
+# git is needed to pip install latex2sympy from GitHub.
+RUN dnf install -y git findutils && dnf clean all
 
 WORKDIR /app
 
-RUN yum install -y git
+ENV PYTHONPATH=/app
 
 # Copy and install any packages/modules needed for your evaluation script.
 COPY requirements.txt .
 RUN pip3 install -r requirements.txt
 
+# The healthcheck command runs the pytest suite
+RUN pip3 install pytest
+
 # Copy the evaluation and testing scripts
 COPY evaluation.py ./app/
-COPY evaluation_test.py ./app/
+COPY evaluation_tests.py ./app/
 
 # Copy the preview and testing scripts
 COPY preview.py ./app/
-COPY preview_test.py ./app/
+COPY preview_tests.py ./app/
 
 # Copy additional files
 COPY static_unit_conversion_arrays.py ./app/
@@ -30,5 +36,6 @@ COPY docs/user.md ./app/docs/user.md
 RUN chmod 644 $(find . -type f)
 RUN chmod 755 $(find . -type d)
 
-# The entrypoint for AWS is to invoke the handler function within the app package
-CMD [ "/app/app.handler" ]
+# The entrypoint for AWS is to invoke the handler function within the app package.
+# Python 3.12's Lambda runtime imports this as a module name, so it can't be a path.
+CMD [ "app.handler" ]
diff --git a/app/evaluation_test.py b/app/evaluation_tests.py
similarity index 100%
rename from app/evaluation_test.py
rename to app/evaluation_tests.py
diff --git a/app/preview_test.py b/app/preview_tests.py
similarity index 100%
rename from app/preview_test.py
rename to app/preview_tests.py
diff --git a/app/requirements.txt b/app/requirements.txt
index 1f9031a..670bf6a 100755
--- a/app/requirements.txt
+++ b/app/requirements.txt
@@ -1,5 +1,5 @@
 typing_extensions
 mpmath==1.2.1
-sympy==1.10.1
+sympy==1.12.1
 antlr4-python3-runtime==4.7.2
 git+https://github.com/lambda-feedback/latex2sympy.git@master#egg=latex2sympy2
\ No newline at end of file
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..589497f
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,4 @@
+[pytest]
+# evaluation_tests.py is the name the base layer's healthcheck imports, so
+# include it alongside pytest's default patterns.
+python_files = test_*.py *_test.py *_tests.py