Worked on the xupefei/delta repository to enhance the robustness of Delta Lake’s history time travel feature, specifically addressing stability during parallel search operations. Focused on defensive error handling by ensuring empty partition histories are managed gracefully, which prevents NoSuchElementException crashes when traversing historical data. Implemented targeted tests to verify correct behavior in scenarios involving empty histories and parallel searches, thereby improving reliability for users conducting history-based data analysis. Utilized Java and Scala within a distributed systems context, emphasizing Spark integration. The work reduced user-facing errors and downtime, supporting smoother and more dependable exploration of historical data states.