Worked on the Shopify/rails repository to enhance data integrity in bulk database operations by implementing comprehensive tests for duplicate handling in insert_all and upsert_all methods. Focused on verifying that the correct values are applied when duplicate identifiers are encountered, the work expanded test coverage and reduced the risk of regressions during future refactors. Leveraged Ruby on Rails and Ruby to design and automate these tests, ensuring clear commit traceability and safer iteration for bulk insert and upsert workflows. This approach enabled more reliable and maintainable code, supporting faster development cycles and improving confidence in the system’s handling of complex data scenarios.