Eduardo Fernandes enhanced data integrity and system reliability across the qub-it/fenixedu-academic and qub-it/fenixedu-oss-dependency-management repositories. He introduced regex-based validation logic for PersonIdentifierType, ensuring that identifiers conform to defined patterns and providing clear error messages for invalid formats or patterns. This backend development work, implemented in Java and DML, reduced the risk of invalid data entering the system. Additionally, Eduardo upgraded the academic-core dependency to version 50.6.0, addressing security and feature updates. His contributions demonstrated a methodical approach to data modeling and dependency management, laying groundwork for future identifier-based features and improving maintainability.