Alex Ionescu is VP of Endpoint Engineering at CrowdStrike, Inc., where he started as the Founding Chief Architect in 2011. Alex is a world-class security architect and consultant expert in low-level system software, kernel development, security training, and reverse engineering. He is co-author of the last 3 editions of the Windows Internals series. During the last two decades, his work led to the fixing of dozens of critical kernel vulnerabilities in Windows. Previously, Alex was the lead kernel developer for ReactOS, an open source Windows clone written from scratch, for which he wrote most of the Windows NT-based subsystems. During his studies in Computer Science, Alex worked at Apple on the iOS kernel, boot loader, and drivers on the original core platform team behind the iPhone, iPad, and AppleTV. Alex is also the founder of Winsider Seminars & Solutions Inc., a company that specializes in low-level system software, reverse engineering and security training for various institutions.