Microsoft's Enterprise & Security group in ILDC is expanding and seeking a Senior Software Engineer to join their founding team. This role focuses on securing user identity and data through advanced operating system technologies. You'll work on critical security infrastructure including crypto algorithms, certificate trust, key isolation, and application isolation technologies across Windows and Linux platforms. The position offers the opportunity to impact billions of devices, from PCs to cloud servers, while working with cutting-edge virtualization-based security technologies. The team's work is fundamental to Microsoft's product lines, powering Azure Cloud security and device management solutions worldwide. This role combines deep technical expertise in OS internals with security innovation, offering a chance to directly influence global OS security standards. The position offers comprehensive benefits, hybrid work arrangements, and the opportunity to work with industry-leading technologies in a collaborative environment.