Worked on the spring-data-elasticsearch repository, focusing on backend development to enhance the stability and correctness of Elasticsearch update operations. Addressed a critical issue by aligning the datatypes of PrimaryTerm and SeqNo in UpdateQuery from Integer to Long, ensuring compatibility with Elasticsearch field expectations and preventing data truncation errors. This change improved the reliability of document updates, reducing the risk of production-time failures and data inconsistencies. The work emphasized data integrity and operational robustness rather than feature expansion, utilizing Java and Elasticsearch expertise to deliver targeted bug fixes that strengthened the update paths within the existing codebase over the month.