Worked on the lmtsufape/hvu repository to enhance backend security and streamline the data model. Focused on implementing role-based access control for protected API routes, requiring users to have either MEDICOLAPA or SECRETARIOLAPA roles, using Java and Spring Security. Simplified the codebase by removing the LivroRegistro entity along with its related controllers, services, and repositories, reducing maintenance overhead and potential sources of bugs. All modifications were consolidated into a single, traceable commit, ensuring clear change management. This work improved maintainability, reduced the code surface area, and made onboarding and future development more efficient for the backend API system.