David Blasby developed a configurable outgoing header disallow feature for the geonetwork/core-geonetwork repository, focusing on enhancing proxy control and security. He introduced a new disallowHeaders configuration parameter, allowing administrators to specify which headers should be excluded from outgoing proxy requests. By overriding the copyRequestHeader method in Java, David ensured that these specified headers are removed before requests are forwarded, effectively reducing the risk of header leakage. His work demonstrated strong backend development and proxy configuration skills, delivering a targeted solution that enables more granular control over proxy behavior within the Java-based geonetwork/core-geonetwork codebase during December 2024.