Architecture

• Frontend: React (Vite), AWS Amplify for auth/storage, hosted via Amplify (or GitHub Pages for docs only).
• Backend: Express on Elastic Beanstalk (EC2), integrates with OpenAI and Deezer.
• Data: MongoDB Atlas (user_songs collection with ELO ranking).
• Auth: Cognito (email/password and Google).
• Media: S3 for profile pictures.
• DNS: Route 53 -> Amplify.

A high-level diagram can be added here.