Worked on the matomo-org/matomo repository to improve the reliability of campaign name rendering in transitions event analytics. Addressed a bug by refactoring the backend PHP logic, replacing the use of CONCAT with CONCAT_WS to handle potential null values in referer_name and referer_keyword fields. This adjustment ensured that campaign attribution data in transitions events became more consistent and accurate, directly benefiting downstream analytics. The solution was validated through targeted tests and code review, confirming no regressions in data processing. Demonstrated backend development skills and attention to data quality, focusing on robust handling of edge cases within the analytics pipeline.