Skilled PHP, JavaScript Developer Needed | Payment will be made only after project complete

I'm seeking an accomplished PHP and JavaScript developer who has at least 8 years of experience. You must be adept at core PHP development without any dependence on frameworks. Key duties for this project will include:

- Implementing user authentication
- Integrating databases
- Integrating payment gateways

Please only bid if you have an extensive background in both PHP and JavaScript, and are comfortable with core PHP development.
Note :
Payment will be made only after project complete