< Back to search
Microsoft UK • London, United Kingdom

Principal Data Scientist

Employment type:  Full time
< Back to search
9.8

/10

Transparency ranking

top 3
scores:
83%

Location flexibility

81%

Hours flexibility

79%

Autonomy

Apply now

Job Description

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

#M365CORE

Microsoft is an equal opportunity employer. Consistent with applicable law, 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 and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.

Company benefits

Wellbeing allowance
Health insurance
Dental coverage
Gym membership
Mental health platform access
Buy or sell annual leave
Shared parental leave
Charity donation scheme
Employee assistance programme
Employee discounts
Volunteer days
Fertility treatment leave
Open to compressed hours
Open to job sharing
Fertility benefits
Enhanced sick pay
Enhanced sick days
Compassionate leave
Travel insurance
20 days annual leave + bank holidays
Enhanced maternity leave
Enhanced paternity leave
Adoption leave
Childcare credits
Carer’s leave
Cycle to work scheme
Faith rooms
Annual bonus
Annual pay rises
Company car
Hackathons
Open to part-time employees
Pregnancy loss leave
Life insurance
Equity packages
Financial coaching
Relocation packages
Sabbaticals
Enhanced pension match/contribution

Working at Microsoft UK

Company employees

Globally: 228,000

Gender diversity (male:female)

67:33

Currently Hiring Countries

United Kingdom

Office Locations

Awards & Achievements

Family Friendly

Family Friendly

Flexa awards 2025
Career Progression

Career Progression

Flexa awards 2025
Most flexible companies

Most flexible companies

Flexa100 2024
;