Worked on civicrm-core to deliver a feature that records and persists fee amounts within transaction parameters, enhancing financial tracking and reporting for fee-based transactions. This involved implementing logic in PHP to capture fee data in transaction line items, improving accuracy and reducing manual reconciliation. Later, addressed stability issues by safeguarding trigger rebuild processes against missing backing tables after custom field deletions, using database management techniques to check table existence via information_schema before querying. These changes prevented crashes during trigger rebuilds and custom group checks, resulting in safer field deletion workflows and more robust database operations within the civicrm-core repository.