Principal Software Engineer-M365 Copilot

Microsoft is at the forefront of a new era in productivity, with Microsoft 365 Copilot redefining AI-powered experiences across work. The Copilot and Agents Core Office of the CTO shapes intelligent experiences across Microsoft 365 by bridging research and engineering, building core agent capabilities, incubating emerging technologies, and helping product teams scale high-quality AI features. We partner with engineers, researchers, and product teams to prototype bold ideas, validate them in real-world scenarios, and transition them into production-ready systems. Our culture values curiosity, accountability, collaboration, technical depth, user empathy, continuous learning, and open idea-sharing. By joining this team, you’ll help shape how Copilot and intelligent agents evolve across Microsoft and contribute to intelligent, contextual assistance for millions of users. As a  Principal Software Engineer , you will architect and lead the development of LLMs (Large Language Models) and the supporting subsystems that power product scenarios and GenAI capabilities across Microsoft 365 experiences. You will set technical direction, partner with research and engineering teams to deliver best-in-class solutions, align senior stakeholders, drive the design of custom LLM architectures for product needs, and design the backend, data, and ML systems that empower teams across the organization — while mentoring engineers and raising the technical bar. The ideal candidate is an AI-forward technical leader who thrives in fast-paced, ambiguous environments, sets direction amid uncertainty, and delivers outsized impact through both hands-on engineering and technical leadership. If you’re passionate about building high-quality systems, solving complex technical problems, and elevating the engineers around you, this role is a strong fit. Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees, we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day, we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.

Serve as a technical leader and domain expert for shipping AI- and ML-based intelligent services and products, staying ahead of industry trends and applying them to influence product and platform direction. Lead architectural design for complex backend, data, and ML systems that meet security, compliance, scalability, and reliability requirements, and translate vision into actionable milestones, estimates, and plans. Define and drive engineering quality strategy — establishing metrics, standard practices, and reusable design patterns that raise reliability, maintainability, and developer efficiency across the team. Partner with stakeholders and cross-functional teams — including product managers, applied scientists, and data engineers — to align on requirements, incorporate feedback, and deliver high-impact features and platform improvements. Lead the creation and improvement of internal tools and frameworks that accelerate developer velocity, automation, and overall system effectiveness. Mentor and grow engineers through code reviews, design reviews, and technical guidance, raising the bar for engineering excellence across the team. Embody our culture and values.

Required Qualifications: Bachelor's Degree in Computer Science or related technical field AND 6+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience.  Other Requirements: Ability to meet Microsoft, customer and/or government security screening requirements are required for this role. These requirements include but are not limited to the following specialized security screenings:   Microsoft Cloud Background Check :