Principal Applied Scientist

Principal Applied Scientist

United Kingdom, London, London

Job description

Company and benefits

Job number

200067070

Date posted

Nov 13, 2026

Work site

3 days / week in-office

Travel

Less than 25%

Profession

Research, Applied, & Data Sciences

Discipline

Applied Sciences

Role type

Individual Contributor

Employment type

Full-Time

Overview

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