diff --git a/backend/Dockerfile b/backend/Dockerfile
index 6c30316..d189c96 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -12,6 +12,7 @@ WORKDIR /app
 RUN apt-get update && apt-get install -y \
     libpq-dev \
     curl \
+    gosu \
     && rm -rf /var/lib/apt/lists/*
 
 # Copy requirements first (Docker layer caching)
@@ -38,7 +39,6 @@ RUN chmod +x startup.sh
 # Create non-root user for security
 RUN useradd -m -u 1001 appuser && \
     chown -R appuser:appuser /app /data
-USER appuser
 
 # Expose backend port
 EXPOSE 8001
diff --git a/backend/startup.sh b/backend/startup.sh
index 56f67e0..b0a3964 100644
--- a/backend/startup.sh
+++ b/backend/startup.sh
@@ -6,6 +6,11 @@ set -e
 
 echo "🚀 Starting Trendyol Product Dashboard Backend..."
 
+# Fix permissions on volume-mounted directories (Coolify mounts as root)
+echo "🔧 Fixing data directory permissions..."
+chown -R appuser:appuser /data 2>/dev/null || true
+chmod -R 755 /data 2>/dev/null || true
+
 # Database URL from environment
 DB_URL="${DATABASE_URL:-postgresql://postgres:trendyol123@postgres:5432/trendyol_db}"
 echo "📦 Database: PostgreSQL"
@@ -48,4 +53,4 @@ echo "✅ Migrations completed!"
 
 # Start the FastAPI application
 echo "🌐 Starting FastAPI server on port 8001..."
-exec uvicorn main:app --host 0.0.0.0 --port 8001 --log-level info
+exec gosu appuser uvicorn main:app --host 0.0.0.0 --port 8001 --log-level info