MERN Stack Guru for Diverse Tasks

I'm in need of a proficient MERN (MongoDB, Express.js, React.js, Node.js) full stack developer with particular experience in MongoDB. Your role will encompass performing a wide variety of database operations including data retrieval, updates, and extensive administration tasks. In addition, there are several key functionalities I require for my project which comprise user authentication and authorization, all CRUD operations, and effective API integration. The ideal candidate should not only have in-depth knowledge of all these, but ideally, a proven track record in executing such tasks successfully. Skills in debugging, problem-solving, and the ability to work independently are also highly desirable.