From Battlefields to Firewalls: William’s Journey Through Pressure, Purpose and Cyber Resilience

William MacMillan, Former CISO at CIA William shares his remarkable journey from serving as a helicopter pilot in the US Air Force to becoming Chief Information Security Officer at the CIA. His early career involved combat rescue and special operations, which fuelled his passion for foreign engagement and international travel. This ultimately led him to a two-decade career with the CIA, where he works across both intelligence operations and cyber defence, culminating in a leadership role at the highest level of national security. His transition into cyber security started in the mid-2000s, driven by a clear recognition that the “adventure” was shifting towards the digital frontier.

He reflects on his career choices as a series of steps toward roles that are “fun, impactful and serve a greater purpose.” William notes that cyber security, much like military service, demands a high degree of resilience and a willingness to work under pressure.…