During July 2025, Hieu Tran developed the foundational data layer for the MockProject_062025_Group03 repository, focusing on robust case management capabilities. He designed and implemented core domain models for Event, FinancialInvest, Inmate, and WitnessInterview, ensuring these entities were cohesively mapped to the database using Java, Hibernate, and JPA. This work established reliable storage and retrieval mechanisms, supporting data integrity and enabling scalable reporting and cross-entity workflows. By aligning the data model with project goals, Hieu created a clean extension path for future features such as audits and analytics, demonstrating depth in backend development and thoughtful entity design within the project scope.