Worked on the Techeer-Hogwarts/backend repository to deliver an admin-only API for closing study recruitments by marking StudyTeam entities as finished. The implementation included robust admin authorization checks and explicit handling for unauthorized access, enhancing both security and auditability. Focused on backend development using Java and Spring Boot, the work also involved targeted refactoring within the StudyTeam module to improve maintainability and testability. Code formatting and quality standards were enforced through spotlessApply, ensuring alignment with project guidelines. No bugs were fixed during this period, with efforts concentrated on feature delivery and code quality improvements in RESTful API development.