Chelsea Liu developed a Bulgarian EGN checksum validation feature for the DataDog/dd-sensitive-data-scanner repository, expanding the platform’s ability to accurately identify and validate sensitive personal data. She designed a dedicated validator struct in Rust, implementing is_valid_match logic to compute and verify EGN checksums, and integrated this validator into the scanner’s configuration for seamless support of Bulgarian identifiers. Chelsea also wrote comprehensive unit tests to cover both valid and invalid EGN scenarios, ensuring reliability and regression safety. Her work in backend development, checksum algorithms, and data validation enhanced compliance and improved the accuracy of sensitive data scanning for Bulgarian data.