Principal Applied Scientist

We’re looking for a Principal Applied Scientist to help shape the intelligence and reasoning capabilities at the heart of Copilot. This role is ideal for a scientific leader with deep expertise in generative AI, machine learning, and deep learning, and a solid track record of translating advances in AI into innovative, user-facing experiences at scale.

As part of the Copilot and Agents Core (CACore) organization, you will work on Copilot Chat Orchestration, bringing together LLM reasoning, tools, and enterprise knowledge to create intelligent, context-aware Copilot experiences. The scientific challenges span LLM reasoning and planning, agentic systems, tool use and orchestration, grounding, evaluation, and the rapidly evolving capabilities of frontier models.

You will work closely with applied scientists, engineers, and product managers to define and advance the scientific direction of these systems. You will lead ambitious initiatives from early exploration and experimentation through to production, developing new approaches, establishing rigorous evaluation methodologies, and translating research breakthroughs into reliable, high-quality AI capabilities.

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

• Lead the scientific direction for Copilot Chat Orchestration, defining the experimentation roadmap that advances reasoning, grounding, tool use and agentic capabilities.

• Lead high-impact initiatives from problem formulation through production deployment, delivering measurable improvements in quality, reliability, latency, cost efficiency and customer value.

• Develop novel approaches to multi-step reasoning, planning, retrieval-augmented generation, tool orchestration and reinforcement-learning-based optimization.

• Establish rigorous evaluation methodologies spanning offline benchmarks, online experimentation and large-scale telemetry, shaping success criteria and informing product and model decisions.

• Drive deep investigations into model behavior and orchestration failure modes, translating findings into systematic improvements and strategic investments.

• Influence architectural and technical decisions across science, engineering and product teams, resolving complex trade-offs and aligning stakeholders around evidence-based approaches.

Qualifications

Required Qualifications:

• Bachelor's Degree or more in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND related experience (e.g., statistics, predictive analytics, research) 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:

• Relevant experience in applied research or industry, developing and evaluating machine learning or AI systems.
• Solid grounding in experimental design, statistical analysis, offline evaluation and online experimentation to guide model and product decisions.
• Solid communication skills, with the ability to explain complex scientific concepts and technical trade-offs to diverse audiences.
• A Ph.D. in Computer Science, Math, Physics, Statistics, or related areas.
• Extensive experience in machine learning, natural language processing, information retrieval, recommendation systems or related fields.
• Deep expertise in machine learning, deep learning and generative AI, with demonstrated experience developing and evaluating LLM-based systems.
• Experience developing and evaluating agentic systems involving multi-step reasoning, planning, retrieval-augmented generation and tool orchestration.
• Professional experience developing ML models for scaled production services, with a proven track record of successfully shipping applied research to production.

Applied Sciences IC6 - The typical base pay range for this role across United Kingdom is £ 119,100.00 - £ 178,700.00 per year. Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here:

https://careers.microsoft.com/v2/global/en/corporate-pay/united-kingdom-corporate-pay.html

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.