diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 9e7c193..b0eac51 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -32,7 +32,7 @@ jobs:
           python-version: "3.12"
           cache: "poetry"
       - name: Install dependencies
-        run: poetry install --all-extras
+        run: poetry install --all-extras --with dev
       - name: Run gitlint
         run: poetry run gitlint --contrib contrib-title-conventional-commits
       - name: Run ruff check
@@ -120,7 +120,7 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends util-linux unoconv libreoffice-writer
-          poetry install --all-extras
+          poetry install --all-extras --with dev
       - name: Set environment
         run: |
           echo "ENV=dev" >> .env
diff --git a/Dockerfile b/Dockerfile
index 0079767..ff64f38 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,16 +1,40 @@
+FROM python:3.12 AS build
+
+ARG ENV=docker
+
+ENV PYTHONUNBUFFERED=1
+ENV POETRY_VIRTUALENVS_CREATE=false
+ENV POETRY_HOME=/opt/poetry
+ENV APP_HOME=/app
+
+WORKDIR $APP_HOME
+
+RUN pip install -U poetry
+
+# Install project dependencies
+COPY pyproject.toml poetry.lock $APP_HOME/
+RUN \
+  --mount=type=cache,target=.cache/pypoetry \
+  poetry install --no-root --all-extras $(test "$ENV" = "dev" && echo "--with dev")
+
+# Install project itself
+COPY . $APP_HOME
+RUN \
+  --mount=type=cache,target=.cache/pypoetry \
+  poetry install --only-root
+
 FROM python:3.12-slim
 
+ARG UID=901
+
 # Needs to be set for users with manually set UID
 ENV HOME=/home/document-merge-service
-
-ENV PYTHONUNBUFFERED=1
 ENV DJANGO_SETTINGS_MODULE=document_merge_service.settings
-ENV APP_HOME=/app
 ENV UWSGI_INI=/app/uwsgi.ini
 ENV MEDIA_ROOT=/var/lib/document-merge-service/media
 ENV DATABASE_DIR=/var/lib/document-merge-service/data
 
-ARG UID=901
+WORKDIR $APP_HOME
 
 RUN mkdir -p $APP_HOME $DATABASE_DIR/tmp $MEDIA_ROOT /var/www/static \
   && useradd -u $UID -r document-merge-service --create-home \
@@ -21,30 +45,24 @@ RUN mkdir -p $APP_HOME $DATABASE_DIR/tmp $MEDIA_ROOT /var/www/static \
   # root.
   && chown -R document-merge-service:root $DATABASE_DIR $MEDIA_ROOT $HOME /var/www/static
 
-WORKDIR $APP_HOME
-
 RUN \
-  --mount=type=cache,target=/var/cache/apt \
+  --mount=type=cache,target=/var/cache/apt,sharing=locked \
+  --mount=type=cache,target=/var/lib/apt,sharing=locked \
   apt-get update && apt-get install -y --no-install-recommends \
-    build-essential \
     default-libmysqlclient-dev \
     libreoffice-writer \
-    pkg-config \
     unoconv \
     util-linux \
     wait-for-it \
   && rm -rf /var/lib/apt/lists/*
 
-RUN pip install -U poetry
-
 USER document-merge-service
 
-ARG ENV=docker
-COPY pyproject.toml poetry.lock $APP_HOME/
-RUN if [ "$ENV" = "dev" ]; then poetry install --no-root --all-extras; else poetry install --no-root --all-extras --without dev; fi
-
-COPY . $APP_HOME
+COPY --from=build /usr/local/lib/python3.12/site-packages/ /usr/local/lib/python3.12/site-packages/
+COPY --from=build /usr/local/bin/ /usr/local/bin/
 
 EXPOSE 8000
 
-CMD /bin/sh -c "poetry run python ./manage.py migrate && poetry run uwsgi"
+COPY . $APP_HOME
+
+CMD ["/bin/sh", "-c", "./manage.py migrate && uwsgi"]
diff --git a/docker-compose.override.yml b/docker-compose.override.yml
index cd3dcd4..bc0548f 100644
--- a/docker-compose.override.yml
+++ b/docker-compose.override.yml
@@ -17,7 +17,7 @@ services:
       [
         "/bin/sh",
         "-c",
-        "poetry run python ./manage.py migrate && poetry run python ./manage.py runserver 0.0.0.0:8000"
+        "./manage.py migrate && ./manage.py runserver 0.0.0.0:8000"
       ]
     environment:
       - ENV=dev
diff --git a/poetry.lock b/poetry.lock
index c34a61c..252138c 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -509,6 +509,7 @@ files = [
     {file = "cryptography-44.0.0-cp37-abi3-manylinux_2_28_aarch64.whl", hash = "sha256:761817a3377ef15ac23cd7834715081791d4ec77f9297ee694ca1ee9c2c7e5eb"},
     {file = "cryptography-44.0.0-cp37-abi3-manylinux_2_28_x86_64.whl", hash = "sha256:3c672a53c0fb4725a29c303be906d3c1fa99c32f58abe008a82705f9ee96f40b"},
     {file = "cryptography-44.0.0-cp37-abi3-manylinux_2_34_aarch64.whl", hash = "sha256:4ac4c9f37eba52cb6fbeaf5b59c152ea976726b865bd4cf87883a7e7006cc543"},
+    {file = "cryptography-44.0.0-cp37-abi3-manylinux_2_34_x86_64.whl", hash = "sha256:60eb32934076fa07e4316b7b2742fa52cbb190b42c2df2863dbc4230a0a9b385"},
     {file = "cryptography-44.0.0-cp37-abi3-musllinux_1_2_aarch64.whl", hash = "sha256:ed3534eb1090483c96178fcb0f8893719d96d5274dfde98aa6add34614e97c8e"},
     {file = "cryptography-44.0.0-cp37-abi3-musllinux_1_2_x86_64.whl", hash = "sha256:f3f6fdfa89ee2d9d496e2c087cebef9d4fcbb0ad63c40e821b39f74bf48d9c5e"},
     {file = "cryptography-44.0.0-cp37-abi3-win32.whl", hash = "sha256:eb33480f1bad5b78233b0ad3e1b0be21e8ef1da745d8d2aecbb20671658b9053"},
@@ -519,6 +520,7 @@ files = [
     {file = "cryptography-44.0.0-cp39-abi3-manylinux_2_28_aarch64.whl", hash = "sha256:c5eb858beed7835e5ad1faba59e865109f3e52b3783b9ac21e7e47dc5554e289"},
     {file = "cryptography-44.0.0-cp39-abi3-manylinux_2_28_x86_64.whl", hash = "sha256:f53c2c87e0fb4b0c00fa9571082a057e37690a8f12233306161c8f4b819960b7"},
     {file = "cryptography-44.0.0-cp39-abi3-manylinux_2_34_aarch64.whl", hash = "sha256:9e6fc8a08e116fb7c7dd1f040074c9d7b51d74a8ea40d4df2fc7aa08b76b9e6c"},
+    {file = "cryptography-44.0.0-cp39-abi3-manylinux_2_34_x86_64.whl", hash = "sha256:9abcc2e083cbe8dde89124a47e5e53ec38751f0d7dfd36801008f316a127d7ba"},
     {file = "cryptography-44.0.0-cp39-abi3-musllinux_1_2_aarch64.whl", hash = "sha256:d2436114e46b36d00f8b72ff57e598978b37399d2786fd39793c36c6d5cb1c64"},
     {file = "cryptography-44.0.0-cp39-abi3-musllinux_1_2_x86_64.whl", hash = "sha256:a01956ddfa0a6790d594f5b34fc1bfa6098aca434696a03cfdbe469b8ed79285"},
     {file = "cryptography-44.0.0-cp39-abi3-win32.whl", hash = "sha256:eca27345e1214d1b9f9490d200f9db5a874479be914199194e746c893788d417"},
@@ -3145,4 +3147,4 @@ s3 = ["boto3"]
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.10.0,<3.13"
-content-hash = "489e50dee6404318973b37dc46b6d232fe72732e3f4fffb8bf161a4762cbdadf"
+content-hash = "b80931356526abebde4e791ede6178d0ae440667f8e960a8489f21e05f6720fc"
diff --git a/pyproject.toml b/pyproject.toml
index 552d738..0d1cb30 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -50,6 +50,9 @@ uWSGI = "^2.0.21"
 xltpl = "~0.21"
 poetry = "^2.0.0"
 
+[tool.poetry.group.dev]
+optional = true
+
 [tool.poetry.group.dev.dependencies]
 django-stubs = "5.1.1"
 factory-boy = "3.3.1"