Mark Russinovich is a prominent software engineer and technology expert known for his work in the field of computer systems and operating systems. He is a co-founder of Winternals Software, which specialized in system utilities for Microsoft Windows. In 2006, Microsoft acquired Winternals, and Russinovich became a Technical Fellow at Microsoft, where he focuses on the development of the Windows operating system. In addition to his engineering work, Russinovich is an accomplished author and speaker. He has written several books, including "Windows Internals," which is widely regarded as a definitive guide to the inner workings of the Windows operating system. His contributions to the tech community also include various tools and utilities that help IT professionals troubleshoot and manage Windows systems.