Comprehensive App Backend Development

I'm in need of a skilled backend developer with extensive experience in JavaScript, React, Node, and MongoDB. The project involves complete backend design and development for an app.

Key Responsibilities:
- User Authentication: Implement robust user authentication systems to ensure secure access.
- Database Management: Efficiently manage the app's database to ensure smooth operations.
- API Development: Design and develop a comprehensive RESTful API for the app.

The ideal candidate should have:
- Proficiency in JavaScript, React, Node, and MongoDB.
- Extensive experience in User Authentication, Database Management, and RESTful API development.
- Ability to implement CRUD operations, User authentication and authorization, and Data validation within the API.

Looking forward to your bids.