build an API that retrieves data from the database and returns it in JSON format

I am looking for a developer to build an API that retrieves data from my MySQL database and returns it in JSON format. The ideal candidate should have experience with PHP and OAuth authentication. The API should also be able to handle large amounts of data and should be optimized for speed. The following requirements should be met:

- Retrieve data from MySQL database
- Return data in JSON format
- Implement OAuth authentication
- Optimize API for speed and handling of large amounts of data