Worked on stabilizing the Department service within the ihub-pub/RuoYi-Vue-Plus repository, focusing on backend development and code optimization using Java. Addressed a key bug by removing redundant null checks and refactoring the DepartmentService implementation, which streamlined stream operations through a utility-based approach. This technical refinement improved code efficiency and readability, reducing complexity and lowering the risk of null-related runtime errors. The changes enhanced maintainability and established a cleaner foundation for future development. By prioritizing code quality and maintainability, the work supported faster onboarding for new contributors and facilitated future feature enhancements within the Department module.