Principal Software Engineer - Copilot Identity

Consumer Copilot Security is at the core of Microsoft’s mission to deliver trusted, human-centered AI experiences. We make security and resilience intrinsic to every Copilot interaction—across devices, platforms, and ecosystems. Our work spans secure identity flows, defenses against emerging threats like prompt injection, and privacy-first systems that scale globally. Copilot for consumers depends on a rock-solid identity foundation that makes personalized AI experiences safe and seamless across Windows, Edge, web, and mobile. We’re seeking a hands-on Principal Software Engineer to define and lead the strategy for authentication, authorization, and account systems across Copilot experiences, partnering deeply with Microsoft’s central identity platform and related teams. You’ll tackle novel risks at the frontier of agential AI, applying proven solutions and inventing new ones where needed. This role demands a rare blend of deep backend engineering expertise, mastery of modern consumer identity protocols, and the ability to make sound trade-offs between risk and velocity—keeping Copilot moving fast while raising the security and reliability bar. Your work will secure AI experiences for hundreds of millions of users worldwide, shaping how people trust and interact with Microsoft’s most transformative products. If you thrive on solving hard technical problems at scale, influencing architecture across platforms, and building systems that balance speed and trust, this is your opportunity to make a global impact.