During December 2024, Kruemel developed robust persistence for Java date and time types in PostgreSQL within the eugenp/tutorials repository. They introduced a new DateTimeValues entity and repository, leveraging JPA and the Java Date and Time API to ensure accurate storage and retrieval of temporal data. Integration and end-to-end tests were implemented to verify correct behavior across various Java time types, enhancing reliability for time-based analytics and reporting. By aligning the data model closely with the Java Time API and improving test coverage, Kruemel reduced regression risk and improved traceability, demonstrating a focused and in-depth approach to backend engineering.