diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..02e831d
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,39 @@
+# Git
+.git
+.gitignore
+
+# Python
+__pycache__
+*.py[cod]
+*.egg-info
+.eggs
+venv/
+.venv/
+
+# Instance data (user creates fresh)
+frontends/web/instance/
+frontends/web/certs/
+instance/
+
+# Test data
+test_data/
+tests/
+
+# Pi-specific
+rpi/
+*.img
+*.img.zst
+*.img.zst.zip
+
+# Docs
+*.md
+docs/
+
+# IDE
+.vscode/
+.idea/
+
+# Misc
+*.log
+*.tmp
+.DS_Store
diff --git a/Dockerfile b/Dockerfile
index 8f7bf95..65f759a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -62,8 +62,8 @@ COPY src/ src/
 COPY data/ data/
 COPY frontends/web/ frontends/web/
 
-# Create upload directory
-RUN mkdir -p /tmp/stego_uploads
+# Create upload directory and instance directories (for volumes)
+RUN mkdir -p /tmp/stego_uploads /app/frontends/web/instance /app/frontends/web/certs
 
 # Create non-root user
 RUN useradd -m -u 1000 stego && chown -R stego:stego /app /tmp/stego_uploads