Principal Software Engineer-M365 Copilot
Confirmed on the employer's own hiring board on Sep 27, 2026. First seen by Alion on Sep 21, 2026.
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.
Responsibilities
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.
Qualifications
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: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two years thereafter.
Preferred Qualifications:
- 6+ years experience designing, implementing, and operating large-scale, distributed backend, data-intensive, or ML-driven and evaluation systems in production.
- Demonstrated ability to set technical direction, influence architecture, and mentor engineers to deliver measurable impact in fast-paced and ambiguous environments.
- Proven ability to drive cross-team engineering initiatives, balancing hands-on contributions with strategic technical leadership.
- 5+ years’ experience developing and deploying AI/ML or GenAI products or systems at multiple points in the product cycle from ideation to shipping.
- Experience architecting and operating large-scale distributed systems, data platforms, or ML pipelines in production.
- Experience working with SOTA AI tooling to accelerate software development lifecycle.
- Experience with Azure platforms and modern deployment practices such as CI/CD, containerization, and microservices.
- Experience defining and tracking engineering metrics such as performance, reliability, and observability, and mentoring engineers to raise technical quality.
- A growth mindset, passion for continuous learning, and drive to make both systems and teams more efficient and effective.
#CAP #Copliot
Software Engineering IC5 - The typical base pay range for this role across the U.S. is USD $142,800 - $274,800 per year. There is a different range applicable to specific work locations, within the San Francisco Bay area and New York City metropolitan area, and the base pay range for this role in those locations is USD $188,000 - $304,200 per year.
Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here:
https://careers.microsoft.com/us/en/us-corporate-pay
This position will be open for a minimum of 5 days, with applications accepted on an ongoing basis until the position is filled.
Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship, color, family or medical care leave, gender identity or expression, genetic information, immigration status, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran or military status, race, ethnicity, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable local laws, regulations and ordinances. If you need assistance with religious accommodations and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.