Principal Data Scientist (London)

Microsoft's mission is to empower every person and every organization on the planet to achieve more. Microsoft believes that artificial intelligence will play a critical role in accomplishing that mission.

We're looking for a Principal Data Scientist to help shape the future of Microsoft 365 Copilot, with a focus on Search, Chat and Research experiences.This role sits within the Microsoft Search, Assistant, and Intelligence (MSAI) organization, which powers the intelligence behind M365 Copilot by combining cutting-edge advances in generative AI with personalized search and recommendation systems. As a Principal Scientist in MSAI, you will work in an exciting and fast-paced, collaborative environment. You'll bring deep expertise in large language models (LLMs), information retrieval, and machine learning to improve the quality and scalability of M365 Copilot.You'll partner closely with engineering and product teams to innovate, design and evaluate end-to-end AI solutions that serve millions of enterprise users.This is a high-impact role where you'll influence technical strategy, shape product direction, and collaborate across Microsoft to deliver AI-powered experiences that help users accomplish more with less effort. Responsibilities: You'll work on high-impact, technically ambitious projects that directly shape the future of Microsoft 365 Copilot.Examples include:

• Advancing deep reasoning in Microsoft 365 Copilot by applying next-generation LLM fine-tuning and reinforcement learning techniques.
• Improving Copilot Chat and Researcher response quality through state-of-the-art grounding data selection strategies.
• Enhancing Copilot Search by developing novel content representation models.
• Building the next wave of recommendation and personalization capabilities across M365 Copilot experiences.
• In addition to driving innovation, you'll help grow the team's technical depth by mentoring and developing talent.

Qualifications: Required Qualifications:

• A Ph.D. in Computer Science, Math, Physics, Statistics, OR related areas is highly preferred. Candidates with master's degree with proven industry experience or a strong publication record in the areas of Information Retrieval, Machine Learning, Natural Language Processing, and Deep Learning are considered as well.

• Extensive hands-on experience building and deploying products using Machine Learning. Specifically, we are looking for expertise in Natural Language Processing, Large Language Models, Information Retrieval, and Recommendation Systems with a good understanding of techniques like Differential Privacy, Responsible AI and related areas.

• High proficiency in deploying machine learning applications at scale in real production environments and proven track record of successfully shipping applied research to production is a must

• Excellent problem solving and data analysis skills and a good grasp of applied statistics. Particularly, expertise in developing or applying predictive analytics, statistical modelling, data mining, or machine learning algorithms, especially at scale

• Strong people leadership skills to influence others, with the ability to tech-lead, understand team dynamics, retain, attract, and develop team members.

• Grounded in growth mindset, and advocate for diversity and inclusion.

• Customer obsession and passionate about product impact

• Excellent verbal and written communication skills, with the ability to simplify and explain complex ideas.

• Effective collaboration skills while working effectively within a globally distributed organization.

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:

• PhD degree in Computer Science, Statistics, Mathematics, OR a related field.

• Proven track record in training large language models and post-training large language models, using reinforcement learning or similar techniques

• First-hand experience building agentic AI models using deep learning

Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, color, family or medical care leave, gender identity or expression, genetic information, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran status, race, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable laws, regulations and ordinances. If you need assistance and/or a reasonable accommodation due to a disability during the application or the recruiting process, please send a request via the Accommodation request form . Benefits/perks listed below may vary depending on the nature of your employment with Microsoft and the country where you work. #M365CORE #J-18808-Ljbffr