Worked on the ie3-institute/PowerSystemDataModel repository, delivering a refactor of the JointGridContainer persistence layer to streamline and stabilize data handling. The approach involved extracting raw grid elements, system participants, and graphic elements through the allEntitiesAsList() method, which reduced verbosity and simplified the persistJointGrid process. This change improved maintainability and set a clearer foundation for future enhancements. The work was implemented in Java, leveraging skills in data modeling, database integration, and object-oriented programming. No major bugs were reported during this period, reflecting a focused effort on feature development and codebase clarity rather than reactive maintenance or bug fixing.