During December 2024, Sumeet Varma focused on enhancing the robustness of historical data exploration in the xupefei/delta repository. He addressed a critical issue in Delta Lake’s time travel feature by implementing defensive error handling for empty partition histories, preventing NoSuchElementException crashes during parallel search. Using Scala and Java within the Spark ecosystem, Sumeet introduced targeted tests to verify correct behavior across various time-travel scenarios, ensuring safe traversal even when history is empty. This work improved the reliability of distributed systems handling historical queries, reducing user-facing errors and supporting smoother, more dependable data analysis workflows for downstream users.