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 identifiers. The work involved designing a dedicated validator struct in Rust, implementing checksum algorithms to verify EGN authenticity, and integrating the new logic into the scanner’s configuration for seamless deployment. Comprehensive unit tests were written to cover both valid and invalid EGN cases, ensuring robust data validation and regression safety. This addition enhanced backend data validation capabilities, improved compliance with local data standards, and reduced false positives and negatives in sensitive data scanning for Bulgarian identifiers.