The Microsoft 365 Copilot Reasoning Science team is seeking a Principal Applied Scientist to enhance enterprise productivity through the development of advanced AI capabilities for M365 Copilot Chat. This role focuses on improving frontier-model harness engineering and evaluation, enabling AI agents to perform complex tasks for millions of users. The ideal candidate will thrive in a dynamic environment and work closely with various teams, including Microsoft Research and Azure. This position offers flexibility in work arrangements and emphasizes a culture of innovation and collaboration.

• Bachelor's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 6+ years related experience.
• Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 4+ years related experience.
• Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 3+ years related experience.
• Proficiency in agentic engineering.
• 5+ years experience creating publications such as patents or peer-reviewed academic papers.
• 5+ years building and maintaining production machine learning systems at internet scale.
• 3+ years experience working with multidisciplinary, geo-distributed teams.
• Demonstrated experience owning end-to-end machine learning and software projects.

• Define and manage experiments from inception to shipment, including metrics and ML pipelines.
• Establish rigorous evaluation methodologies and data-driven approaches for measuring model performance.
• Influence senior leadership and partner teams through quality summaries of work and experimentation results.
• Build tools to enhance workflows when off-the-shelf solutions are inadequate.
• Contribute to strategic planning and long-term technical roadmaps to meet business goals.
• Support the growth and development of the team’s engineers and applied scientists.
• Foster a thriving applied science culture to encourage experimentation and innovation.

• Employees at Microsoft are often offered comprehensive, “world-class” benefits—including health and mental-wellness programs, competitive pay with bonuses and stock awards, and retirement/savings options. Time-off and flexibility are common, with generous vacation and holidays, parental and caregiver leave, and flexible work schedules, alongside learning support, employee resource groups, product discounts, and matching-gifts/volunteering programs. Specific benefits can vary by region.