Worked on the geonetwork/core-geonetwork repository to enhance proxy security by implementing a configurable outgoing header disallow feature. Developed a new configuration parameter, disallowHeaders, allowing administrators to specify which headers should be excluded from outgoing proxy requests. This was achieved by overriding the copyRequestHeader method in the Java backend, ensuring that designated headers are removed before requests are forwarded. The approach focused on strengthening proxy control and reducing the risk of header leakage. Leveraged skills in backend development, Java, and proxy configuration to deliver this targeted feature, addressing a specific security need without introducing changes to unrelated areas or fixing existing bugs.