Expert API Development in Python and Java

I'm in search of a qualified Python and Java developer who specializes in API development. A successful candidate should have impressive experience in this field. The API should be custom designed to handle authorization and authentication via API keys.

Primary responsibilities:
- Designing and developing a responsive API in Python and Java
- Implementing secured authorization through API keys

Building APIs for payment gateways- ecomm sites to payment gateways.

Ideal Experience & Skills:
- Significant experience in Python and Java
- Prior work on developing and working with APIs
- Solid understanding of how API keys can be integrated for authentication and authorization
- Able to illustrate their experience eloquently.

Please accompany your application with a detailed representation of your experience in Python, Java, and specifically API development and handling. An API that you've built using API keys for authentication would be an ideal example. Looking forward to your applications!