Job Description: We are urgently looking for an experienced casino developer to fix a critical callback error in our casino system. The system is currently encountering issues with user authentication and transaction validation during callback processing, leading to incorrect error responses and system failures. Required Skills: Strong experience with PHP and MySQL for backend development Expertise in handling API callbacks and troubleshooting errors Familiarity with casino or betting systems is a plus Ability to quickly understand and fix existing code Strong debugging skills and experience with error logging