Duties include PHP / MySQL development of back-end custom billing and accounting solution for high- credit cards, and custom PHP code for user maintenance. Construct, develop and maintain Web applications using a combination of HTML, CSS, JavaScript and PHP. Resolve technical queries of customers regarding API integration, and other issues. Plan, design, develop, debug, implement and support web-based applications. Modify existing software to: correct errors, allow it to function in new operating environments, or improve performance.