diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9c7fd7c..e3ffc52 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,6 +12,7 @@ on:
       - main
       - develop
     types: [opened, synchronize, reopened, ready_for_review]
+  workflow_dispatch:
 
 permissions:
   contents: read
@@ -35,7 +36,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .venv
-          key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('pyproject.toml', 'src/**/*.py') }}
+          key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('requirements.txt', 'requirements-dev.txt') }}
           restore-keys: |
             venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-
 
@@ -44,15 +45,14 @@ jobs:
         run: |
           python -m venv .venv
           .venv/bin/pip install --upgrade pip
-          .venv/bin/pip install ".[dev]"
-
-      - name: Re-install local package (ensures source changes are picked up)
-        if: steps.cache-venv.outputs.cache-hit == 'true'
-        run: .venv/bin/pip install --force-reinstall --no-deps ".[dev]"
+          .venv/bin/pip install -r requirements-dev.txt
 
       - name: Add venv to PATH
         run: echo "${{ github.workspace }}/.venv/bin" >> $GITHUB_PATH
 
+      - name: Set PYTHONPATH
+        run: echo "PYTHONPATH=${{ github.workspace }}/src" >> $GITHUB_ENV
+
       - name: Create .env file for testing
         run: cp .env.example .env
 
diff --git a/Dockerfile b/Dockerfile
index 03e41b5..89d1350 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,7 +6,7 @@ LABEL org.opencontainers.image.description="Dynamischer Formular- & PDF-Generato
 
 WORKDIR /app
 
-# Installiere Systemabhängigkeiten für WeasyPrint (Pango, Cairo, etc.)
+# Layer 1: Systemabhängigkeiten für WeasyPrint (Pango, Cairo, etc.) – ändert sich quasi nie
 RUN apt-get update && apt-get install -y \
     libpango-1.0-0 \
     libpangoft2-1.0-0 \
@@ -16,11 +16,20 @@ RUN apt-get update && apt-get install -y \
     curl \
     && rm -rf /var/lib/apt/lists/*
 
-COPY pyproject.toml .
+# Layer 2: Python-Dependencies – ändert sich nur bei Dependency-Updates
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Layer 3: Anwendungscode – ändert sich häufig, aber nur dieser Layer wird invalidiert
 COPY src/ src/
-RUN pip install --no-cache-dir .
+COPY app.py .
+COPY forms/ forms/
+
+ENV PYTHONPATH=/app/src
 
-COPY . .
+RUN mkdir -p /app/static && cp -r src/formflow/static/. /app/static/
+
+RUN mkdir -p /data/forms /data/pdf_templates
 
 # Statische Dateien (CSS, JS, Standard-Logo) in den festen static-Pfad kopieren,
 # der von Flask als static_folder verwendet wird.
diff --git a/pyproject.toml b/pyproject.toml
deleted file mode 100644
index d59f1ed..0000000
--- a/pyproject.toml
+++ /dev/null
@@ -1,36 +0,0 @@
-[build-system]
-requires = ["setuptools>=69"]
-build-backend = "setuptools.build_meta"
-
-[project]
-name = "formflow"
-version = "0.1.0"
-description = "Dynamischer Formular- & PDF-Generator"
-requires-python = ">=3.11"
-dependencies = [
-    "Flask==3.1.3",
-    "PyYAML==6.0.3",
-    "gunicorn==25.1.0",
-    "WeasyPrint==68.1",
-    "smbprotocol==1.16.0",
-    "pydantic==2.12.5",
-    "pydantic-settings==2.13.1",
-]
-
-[project.optional-dependencies]
-dev = [
-    "pytest==9.0.2",
-    "requests==2.32.5",
-    "pytest-mock==3.15.1",
-]
-
-[tool.setuptools.packages.find]
-where = ["src"]
-include = ["formflow*"]
-
-[tool.setuptools.package-data]
-formflow = [
-    "pdf_templates/*.html",
-    "templates/*.html",
-    "static/**/*",
-]
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..7f82a9a
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,4 @@
+-r requirements.txt
+pytest==9.0.2
+requests==2.32.5
+pytest-mock==3.15.1
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..e786d28
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,7 @@
+Flask==3.1.3
+PyYAML==6.0.3
+gunicorn==25.1.0
+WeasyPrint==68.1
+smbprotocol==1.16.0
+pydantic==2.12.5
+pydantic-settings==2.13.1
diff --git a/update_dependencies.sh b/update_dependencies.sh
index 193eb29..e046be9 100755
--- a/update_dependencies.sh
+++ b/update_dependencies.sh
@@ -10,10 +10,10 @@ echo "🔍 Prüfe auf Updates für alle Abhängigkeiten (das kann einen Moment d
 LATEST_BOOTSTRAP=$(curl -s "https://registry.npmjs.org/bootstrap/latest" | grep -o '"version":"[^"]*"' | head -1 | cut -d'"' -f4)
 LATEST_SIGPAD=$(curl -s "https://registry.npmjs.org/signature_pad/latest" | grep -o '"version":"[^"]*"' | head -1 | cut -d'"' -f4)
 
-# --- 2. Backend (pyproject.toml) ---
-CUR_FLASK=$(grep -i '"Flask==' pyproject.toml | grep -o '[0-9][^"]*' | head -1)
-CUR_WEASYPRINT=$(grep -i '"WeasyPrint==' pyproject.toml | grep -o '[0-9][^"]*' | head -1)
-CUR_SMBPROTO=$(grep -i '"smbprotocol==' pyproject.toml | grep -o '[0-9][^"]*' | head -1 || true)
+# --- 2. Backend (requirements.txt) ---
+CUR_FLASK=$(grep -i 'Flask==' requirements.txt | grep -o '[0-9][^[:space:]]*' | head -1)
+CUR_WEASYPRINT=$(grep -i 'WeasyPrint==' requirements.txt | grep -o '[0-9][^[:space:]]*' | head -1)
+CUR_SMBPROTO=$(grep -i 'smbprotocol==' requirements.txt | grep -o '[0-9][^[:space:]]*' | head -1 || true)
 CUR_FPDF2="(nicht installiert)"
 
 LATEST_FLASK=$(curl -s "https://pypi.org/pypi/Flask/json" | grep -o '"version":"[^"]*"' | head -1 | cut -d'"' -f4)
@@ -39,7 +39,7 @@ echo "📦 Frontend (Lokale Dateien):"
 echo "  Bootstrap:     $BOOTSTRAP_VER -> $LATEST_BOOTSTRAP"
 echo "  Signature Pad: $SIGPAD_VER -> $LATEST_SIGPAD"
 echo ""
-echo "🐍 Backend (pyproject.toml):"
+echo "🐍 Backend (requirements.txt):"
 echo "  Flask:         $CUR_FLASK -> $LATEST_FLASK"
 echo "  WeasyPrint:    $CUR_WEASYPRINT -> $LATEST_WEASYPRINT"
 if [ -n "$CUR_SMBPROTO" ]; then
@@ -72,14 +72,14 @@ then
     echo "🔄 Aktualisiere Konfigurationsdateien..."
 
     # Sicherungsdateien anlegen, damit wir bei Buildfehlern zurückrollen können
-    cp pyproject.toml pyproject.toml.bak
+    cp requirements.txt requirements.txt.bak
     cp Dockerfile Dockerfile.bak
     tar cfz frontend-backup.tar.gz static/css static/js || true
 
-    # Update pyproject.toml
-    sed -i "s/\"Flask==[^\"]*\"/\"Flask==$LATEST_FLASK\"/" pyproject.toml
-    sed -i "s/\"WeasyPrint==[^\"]*\"/\"WeasyPrint==$LATEST_WEASYPRINT\"/" pyproject.toml
-    sed -i "s/\"smbprotocol==[^\"]*\"/\"smbprotocol==$LATEST_SMBPROTO\"/" pyproject.toml
+    # Update requirements.txt
+    sed -i "s/Flask==[^ ]*/Flask==$LATEST_FLASK/" requirements.txt
+    sed -i "s/WeasyPrint==[^ ]*/WeasyPrint==$LATEST_WEASYPRINT/" requirements.txt
+    sed -i "s/smbprotocol==[^ ]*/smbprotocol==$LATEST_SMBPROTO/" requirements.txt
 
     # Update Dockerfile
     sed -i "s/^FROM python:.*/FROM python:$LATEST_PYTHON/" Dockerfile
@@ -102,7 +102,7 @@ then
 
     if [ -n "$BUILD_FAILED" ]; then
         echo "❌ Build fehlgeschlagen – rolle Änderungen zurück."
-        mv pyproject.toml.bak pyproject.toml
+        mv requirements.txt.bak requirements.txt
         mv Dockerfile.bak Dockerfile
         [ -f frontend-backup.tar.gz ] && tar xfz frontend-backup.tar.gz
         exit 1