Reactjs Expert

I am looking for a Reactjs expert to help me with a project that requires specific features and functionalities, including user authentication and authorization, API integration, and responsive design. The project involves debugging existing codebase and needs to be completed within 1 week. I have an existing codebase that needs to be worked on.

Ideal Skills and Experience:
- Strong expertise in Reactjs and its related libraries
- Experience with user authentication and authorization implementation
- Proficiency in API integration and handling
- Ability to create responsive designs
- Familiarity with debugging and troubleshooting existing codebase