Developed a critical accounting feature for the OpenCSGs/csghub-server repository, focusing on enhancing account statement functionality by introducing a recharge purpose data model. Leveraging Go for backend development and database management, the work included implementing validation logic to restrict recharge purposes to predefined values, thereby improving data integrity and supporting policy compliance. Accompanying migration scripts were created to update the database schema, ensuring safer deployments and enabling richer analytics on recharge activities. The feature was delivered end-to-end within the month, with no major bugs reported, demonstrating a methodical approach to backend data modeling, validation, and schema migration tooling.