Architecture highlights:

• Express.js backend connected to MongoDB using Mongoose
• JWT-based authentication and protected route handling
• Password encryption implemented with bcryptjs
• Input validation using express-validator middleware
• Environment-based configuration managed with the config package
• CORS support for secure frontend and backend communication
• Concurrently and Nodemon used for efficient full-stack development workflow

Focused on scalable backend architecture, secure authentication, and maintainable full-stack development practices.