Selected intern’s day-to-day responsibilities include:

1. Aid in designing, developing, and testing server-side applications with Node.js
2. Implement features and functionalities under the guidance of seasoned developers
3. Integrate databases like MongoDB or MySQL for efficient data storage and retrieval
4. Contribute to developing and maintaining RESTful APIs for smooth server-client communication
5. Participate in code reviews to learn and enhance code quality following best practices
6. Collaborate with the team to debug and troubleshoot issues
7. Actively engage in learning sessions and provide training opportunities
8. Stay updated on the latest trends and technologies in Node.js development