Developed enhancements for the NHSDigital/eligibility-signposting-api by implementing new ICB suppression rules within the Eligibility Calculator, focusing on accurate eligibility status determination. The work involved updating backend data builders to incorporate ICB information and expanding automated test coverage to address scenarios where ICB data may be absent or null. Using Python for backend and API development, the approach emphasized robust validation and risk reduction in eligibility calculations. By introducing a suppression rules factory and comprehensive testing, the changes improved the reliability of eligibility assessments, ensuring that the system correctly handles edge cases related to incomplete or missing ICB data during processing.