Worked on the apache/incubator-devlake repository to address a critical data integrity issue affecting cross-project isolation. Focused on backend development and SQL, the developer fixed a bug in the clearHistoryData function by replacing a LEFT JOIN with an INNER JOIN, ensuring deletions were scoped only to the current project’s data. This change prevented accidental removal of pull request links from unrelated projects and improved data governance by filtering deletions to linker-created rows. The solution included an end-to-end test written in Go to validate cross-project isolation, reinforcing safe, repeatable linker runs and reducing risk in multi-project repository environments.