Worked on strengthening the membership renewal process in the civicrm/civicrm-core repository, focusing on ensuring that renewal eligibility, membership types, and end dates accurately reflect payment outcomes. Addressed a key bug by implementing targeted fixes and introducing automated unit tests to validate renewal handling and contribution page configuration. Utilized PHP and CiviCRM, with an emphasis on API integration and unit testing, to improve the reliability of the membership contribution workflow and reduce inconsistencies following payment events. The work enhanced the system’s ability to prevent regressions, resulting in a more robust and predictable experience for both administrators and end users.