During November 2024, Xianghuan Chen focused on backend development and code optimization for the ihub-pub/RuoYi-Vue-Plus repository, specifically targeting the Department service. Chen refactored the DepartmentService implementation in Java, removing redundant null checks and introducing a utility-based approach to streamline stream operations. This work improved the efficiency and readability of the codebase, reducing complexity and lowering the risk of null-related runtime errors. By enhancing maintainability and code quality, Chen established a cleaner foundation for future enhancements and facilitated faster onboarding for new developers. The changes addressed a key bug, demonstrating depth in backend engineering and code optimization.