We are looking for a Senior Applied Scientist with deep expertise in modern retrieval technologies to help shape the future of Microsoft 365 Copilot, with a focus on Search, Chat and Agent experiences. This role sits within the Copilot and Agents Core (CACore) organization, which powers the intelligence behind M365 Copilot by combining cutting-edge advances in generative AI with personalized search, retrieval and recommendation systems. As a Senior Applied Scientist in CACore, you will work in an exciting and fast-paced, collaborative environment focused on building state-of-the-art retrieval systems that serve millions of enterprise users daily.
You will partner closely with engineering, product and platform teams to innovate, design and evaluate retrieval and ranking technologies that improve grounding quality, relevance, personalization and reasoning capabilities across Microsoft 365 Copilot experiences. This is a high-impact role where you will influence technical strategy, shape retrieval architecture, and collaborate across Microsoft Research, Azure AI and product groups to deliver AI-powered experiences that help users accomplish more with less effort.
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.
What You’ll Do
Advance Retrieval Science
Design and run experiments, define offline and online evaluation metrics, and develop scalable retrieval pipelines and models for enterprise-scale search systems.
Areas of focus include:
Semantic retrieval using late-interaction architectures such as ColBERT
Dense retrieval and embedding model fine tuning
Modern lexical retrieval approaches such as SPLADE
Hybrid retrieval systems combining dense + sparse retrieval
Query understanding and representation learning
Multi-stage ranking and retrieval optimisation
Retrieval-augmented generation (RAG)
Personalization and contextual ranking
Knowledge retrieval for agentic AI systems
Reinforcement learning and reasoning-aware retrieval systems
LLM-integrated retrieval architectures
Required Qualifications:
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:
Preferred Qualification:
Applied Sciences IC4 - The typical base pay range for this role across United Kingdom is £ 73,800.00 - £ 121,300.00 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.
Based on 1,371 disclosed Data & ML salaries on RoleSuite, the role pays a median of $165K/year, with most offers between $127K and $210K (10th–90th percentile: $108K–$250K).
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