Stefan Soesanto is a Senior Researcher at the Center for Security Studies (CSS) at ETH Zurich. He leads the Cyberdefense Project and is the Co-Team Head of the Risk and Resilience Team. Prior to joining CSS in 2019, he was the Cybersecurity & Defense Fellow at the European Council on Foreign Relations (ECFR), a non-resident James A. Kelly Fellow at Pacific Forum CSIS, and Research Assistant at RAND. His current research focuses on the war in Ukraine, especially Ukrainian hacktivist and cyber threat groups, as well as digital applications developed by Ukrainian volunteers for the kinetic battlefield.