Worked on backend development for the Netflix/lemur repository, focusing on improving certificate retrieval logic. Addressed an issue where certificates without a Common Name (CN) were incorrectly filtered by replacing a LIKE-based query with a null-safe check using Certificate.cn.is_(None). This adjustment ensured that certificates lacking a specified CN were accurately identified, eliminating false matches and enhancing data integrity. The solution was implemented in Python and demonstrated careful database querying practices. By prioritizing maintainability and correctness, the work contributed to more reliable backend operations and set a standard for handling null values in database-driven applications within the project.