Deploy a Backend Service to Railway

I need to deploy a backend service to Railway with a database and proper production configuration.

Project details:
- Backend framework: [e.g. Express.js, FastAPI, Django, Rails]
- Language/runtime: [e.g. Node.js 20, Python 3.12]
- Database: [e.g. PostgreSQL, MySQL, Redis, or "none"]
- GitHub repo: [repo URL]
- Current local port: [e.g. 3001]
- Services that need to talk to this backend: [e.g. "a Next.js frontend on Vercel", "a mobile app"]

Walk me through the full deployment:

1. Railway project setup:
   - Create a new project and link my GitHub repo
   - Configure the build command and start command
   - Explain how Railway detects my runtime (Nixpacks) and when I need a custom Dockerfile

2. Database provisioning:
   - Add a [database type] instance to my Railway project
   - Show me how to get the connection string
   - Explain the DATABASE_URL format Railway provides
   - Set up the connection in my app using the Railway-provided environment variable

3. Environment variables:
   - List every env var I need to set: [e.g. DATABASE_URL, JWT_SECRET, CORS_ORIGIN, NODE_ENV]
   - Show me how to reference Railway's built-in variables (like $[RAILWAY_TCP_PROXY_PORT])
   - Explain shared variables vs service-specific variables

4. Networking and domain:
   - Generate a Railway public domain
   - Configure CORS to allow requests from [frontend URL]
   - Set up a custom domain if needed
   - Explain Railway's private networking for service-to-service calls

5. Database migrations:
   - Run my migration command on deploy: [e.g. "npx prisma migrate deploy", "python manage.py migrate"]
   - Set up a deploy hook or release command so migrations run automatically before the app starts

6. Monitoring and scaling:
   - Check deployment logs for errors
   - Set up health checks at [e.g. /health or /api/health]
   - Configure auto-sleep for dev environments to save credits
   - Explain Railway's pricing model so I know what to expect on my bill

Give me the exact commands and configuration values. Flag anything that commonly trips people up.