diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 17314a0..7787e3f 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,44 +1,87 @@
+# Copyright 2022 Canonical Ltd.
+# See LICENSE file for licensing details.
 name: Tests
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 on:
   pull_request:
+  schedule:
+    - cron: '53 0 * * *' # Daily at 00:53 UTC
+  # Triggered on push to branch "main" by .github/workflows/release.yaml
   workflow_call:
 
 jobs:
   lint:
     name: Lint
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - name: Checkout
         uses: actions/checkout@v3
-      - name: Install dependencies
+      - name: Install tox
+        # TODO: Consider replacing with custom image on self-hosted runner OR pinning version
         run: python3 -m pip install tox
       - name: Run linters
-        run: tox -e lint
+        run: tox run -e lint
 
   unit-test:
     name: Unit tests
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - name: Checkout
         uses: actions/checkout@v3
-      - name: Install dependencies
-        run: python -m pip install tox
+      - name: Install tox
+        # TODO: Consider replacing with custom image on self-hosted runner OR pinning version
+        run: python3 -m pip install tox
       - name: Run tests
-        run: tox -e unit
+        run: tox run -e unit
+
+  build:
+    name: Build charms
+    uses: canonical/data-platform-workflows/.github/workflows/build_charms_with_cache.yaml@v2
 
   integration-test:
-    name: Integration tests (lxd)
+    strategy:
+      fail-fast: false
+      matrix:
+        tox-environments:
+          - integration
+    name: ${{ matrix.tox-environments }}
     needs:
       - lint
       - unit-test
+      - build
     runs-on: ubuntu-latest
+    timeout-minutes: 120
     steps:
       - name: Checkout
         uses: actions/checkout@v3
       - name: Setup operator environment
+        # TODO: Replace with custom image on self-hosted runner
         uses: charmed-kubernetes/actions-operator@main
         with:
           provider: lxd
           bootstrap-options: "--agent-version 2.9.38"
+      - name: Download packed charm(s)
+        uses: actions/download-artifact@v3
+        with:
+          name: ${{ needs.build.outputs.artifact-name }}
+      - name: Select tests
+        id: select-tests
+        run: |
+          if [ "${{ github.event_name }}" == "schedule" ]
+          then
+            echo Running unstable and stable tests
+            echo "mark_expression=" >> $GITHUB_OUTPUT
+          else
+            echo Skipping unstable tests
+            echo "mark_expression=not unstable" >> $GITHUB_OUTPUT
+          fi
       - name: Run integration tests
-        run: tox -e integration
+        run: tox run -e ${{ matrix.tox-environments }} -- -m '${{ steps.select-tests.outputs.mark_expression }}'
+        env:
+          CI_PACKED_CHARMS: ${{ needs.build.outputs.charms }}
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index e16f5be..4625a7b 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -9,6 +9,7 @@ jobs:
   lib-check:
     name: Check libraries
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - name: Checkout
         uses: actions/checkout@v3
@@ -32,6 +33,7 @@ jobs:
       - lib-check
       - ci-tests
     runs-on: ubuntu-latest
+    timeout-minutes: 60
     steps:
       - name: Checkout
         uses: actions/checkout@v3
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a6da93c..8100ec2 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -55,11 +55,11 @@ pip install -r requirements.txt
 ## Testing
 
 ```shell
-tox -e fmt                      # update your code according to linting rules
-tox -e lint                     # code style
-tox -e unit                     # unit tests
-tox -e integration              # run all integration tests
-tox                             # runs 'lint' and 'unit' environments
+tox run -e format        # update your code according to linting rules
+tox run -e lint          # code style
+tox run -e unit          # unit tests
+tox run -e integration   # integration tests
+tox                      # runs 'lint' and 'unit' environments
 ```
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 39befc1..4e9d36c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,6 +12,7 @@ show_missing = true
 minversion = "6.0"
 log_cli_level = "INFO"
 asyncio_mode = "auto"
+markers = ["unstable"]
 
 # Formatting tools configuration
 [tool.black]
diff --git a/tests/integration/__init__.py b/tests/integration/__init__.py
new file mode 100644
index 0000000..db3bfe1
--- /dev/null
+++ b/tests/integration/__init__.py
@@ -0,0 +1,2 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
new file mode 100644
index 0000000..a5a9e36
--- /dev/null
+++ b/tests/integration/conftest.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+# Copyright 2022 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+import json
+import os
+from pathlib import Path
+
+import pytest
+from pytest_operator.plugin import OpsTest
+
+
+@pytest.fixture
+def ops_test(ops_test: OpsTest) -> OpsTest:
+    if os.environ.get("CI") == "true":
+        # Running in GitHub Actions; skip build step
+        # (GitHub Actions uses a separate, cached build step. See .github/workflows/ci.yaml)
+        packed_charms = json.loads(os.environ["CI_PACKED_CHARMS"])
+
+        async def build_charm(charm_path, bases_index: int = None) -> Path:
+            for charm in packed_charms:
+                if Path(charm_path) == Path(charm["directory_path"]):
+                    if bases_index is None or bases_index == charm["bases_index"]:
+                        return charm["file_path"]
+            raise ValueError(f"Unable to find .charm file for {bases_index=} at {charm_path=}")
+
+        ops_test.build_charm = build_charm
+    return ops_test
diff --git a/tests/integration/test_s3_charm.py b/tests/integration/test_s3_charm.py
index 28847bd..42f99e4 100644
--- a/tests/integration/test_s3_charm.py
+++ b/tests/integration/test_s3_charm.py
@@ -11,7 +11,7 @@
 import yaml
 from pytest_operator.plugin import OpsTest
 
-from tests.integration.helpers import (
+from .helpers import (
     fetch_action_get_connection_info,
     fetch_action_sync_s3_credentials,
     get_application_data,
diff --git a/tests/unit/__init__.py b/tests/unit/__init__.py
new file mode 100644
index 0000000..db3bfe1
--- /dev/null
+++ b/tests/unit/__init__.py
@@ -0,0 +1,2 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
diff --git a/tox.ini b/tox.ini
index a1aa721..ea03738 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,26 +2,26 @@
 # See LICENSE file for licensing details.
 
 [tox]
-skipsdist=True
+no_package = True
 skip_missing_interpreters = True
-envlist = lint, unit
+env_list = lint, unit
 
 [vars]
-src_path = {toxinidir}/src/
-tst_path = {toxinidir}/tests/
-all_path = {[vars]src_path} {[vars]tst_path}
+src_path = {tox_root}/src
+tests_path = {tox_root}/tests
+all_path = {[vars]src_path} {[vars]tests_path}
 
 [testenv]
-setenv =
-  PYTHONPATH = {toxinidir}:{toxinidir}/lib:{[vars]src_path}
-  PYTHONBREAKPOINT=ipdb.set_trace
-  PY_COLORS=1
-passenv =
-  PYTHONPATH
-  CHARM_BUILD_DIR
-  MODEL_SETTINGS
+set_env =
+    PYTHONPATH = {tox_root}/lib:{[vars]src_path}
+    PYTHONBREAKPOINT=ipdb.set_trace
+    PY_COLORS=1
+pass_env =
+    PYTHONPATH
+    CHARM_BUILD_DIR
+    MODEL_SETTINGS
 
-[testenv:fmt]
+[testenv:format]
 description = Apply coding style standards to code
 deps =
     black
@@ -43,9 +43,9 @@ deps =
     isort
     codespell
 commands =
-    codespell {toxinidir} --skip {toxinidir}/.git --skip {toxinidir}/.tox \
-      --skip {toxinidir}/build --skip {toxinidir}/lib --skip {toxinidir}/venv \
-      --skip {toxinidir}/.mypy_cache --skip {toxinidir}/icon.svg
+    codespell {tox_root} --skip {tox_root}/.git --skip {tox_root}/.tox \
+      --skip {tox_root}/build --skip {tox_root}/lib --skip {tox_root}/venv \
+      --skip {tox_root}/.mypy_cache --skip {tox_root}/icon.svg
     # pflake8 wrapper supports config from pyproject.toml
     pflake8 {[vars]all_path}
     isort --check-only --diff {[vars]all_path}
@@ -57,18 +57,22 @@ deps =
     parameterized
     pytest
     coverage[toml]
-    -r{toxinidir}/requirements.txt
+    -r {tox_root}/requirements.txt
 commands =
     coverage run --source={[vars]src_path} \
-        -m pytest --ignore={[vars]tst_path}integration -v --tb native -s {posargs}
+        -m pytest -v --tb native -s {posargs} {[vars]tests_path}/unit
     coverage report
 
 [testenv:integration]
 description = Run integration tests
+pass_env =
+    {[testenv]pass_env}
+    CI
+    CI_PACKED_CHARMS
 deps =
     pytest
     juju==2.9.38.1
     pytest-operator
-    -r{toxinidir}/requirements.txt
+    -r {tox_root}/requirements.txt
 commands =
-    pytest -v --tb native --ignore={[vars]tst_path}unit --log-cli-level=INFO -s {posargs}
+    pytest -v --tb native --log-cli-level=INFO -s {posargs} {[vars]tests_path}/integration/