Principal Applied Scientist

Microsoft Microsoft · Big Tech · Redmond, WA +1 · Applied Sciences

Principal Applied Scientist to define and develop next-gen intelligent, large-scale content platforms for AI-driven experiences. Responsibilities include modeling, experimentation, product impact, and technical leadership in areas like LLMs, information retrieval, ranking, grounding, search systems, and agentic AI. Focus on improving AI system information retrieval, reasoning, multi-turn conversations, tool use, response ranking, and grounded outputs. Requires hands-on experience tuning models at scale (SFT, preference optimization, distillation, data curation, evaluation, experimentation). Role involves leading scientific workstreams, influencing product direction, and collaborating with cross-functional teams.

What you'd actually do

  1. Lead applied science for grounding, search, retrieval, and ranking systems that power Microsoft AI and agent experiences across large-scale content surfaces.
  2. Develop and improve ranking and reranking models for search results, retrieved passages, source selection, answer candidates, tool choices, and agent actions.
  3. Build grounding systems that help AI agents generate reliable, source-backed answers using trusted documents, web content, enterprise data, tool outputs, and user context.
  4. Improve end-to-end search and retrieval quality, including query understanding, semantic and hybrid retrieval, freshness, relevance, source quality, personalization, and latency-aware ranking.
  5. Advance multi-turn agent experiences by improving context understanding, tool use, task completion, clarification behavior, planning, and recovery from errors.

Skills

Required

  • Bachelor's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 6+ years related experience
  • Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 4+ years related experience
  • Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 3+ years related experience
  • equivalent experience

Nice to have

  • Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 9+ years related experience
  • Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 6+ years related experience
  • equivalent experience
  • 10+ industry experience building, evaluating, and deploying machine learning models or AI systems in production.
  • Deep expertise in at least two of the following areas: search, information retrieval, learning-to-rank, recommendation systems, grounded generation, LLM-based ranking, retrieval-augmented generation, conversational AI, or agentic AI systems.
  • Experience with offline and online evaluation, including relevance metrics, A/B experimentation, human evaluation, model diagnostics, and production quality monitoring.
  • Experience working with large-scale datasets, production ML pipelines, distributed training or inference systems, and cross-functional engineering teams.
  • Demonstrated ability to lead ambiguous technical projects as a senior individual contributor and influence product, engineering, and science direction.
  • Communication skills, with the ability to explain scientific tradeoffs clearly to technical and non-technical stakeholders.
  • Experience with production-scale LLM systems, agent frameworks, search engines, ranking systems, or retrieval-augmented generation systems.
  • Experience improving multi-turn AI assistant or agent experiences in real products.
  • Experience with tool-using agents, planning systems, memory, personalization, source ranking, or enterprise search.
  • Experience building evaluation frameworks for factuality, grounding, hallucination, relevance, safety,

What the JD emphasized

  • Deep expertise in large language models, information retrieval, ranking, grounding, search systems, and agentic AI
  • hands-on experience tuning and improving models at scale
  • evaluation design
  • large-scale experimentation
  • lead complex scientific workstreams
  • influence product direction
  • partner closely with engineering, research, and product teams
  • building, evaluating, and deploying machine learning models or AI systems in production
  • Deep expertise in at least two of the following areas: search, information retrieval, learning-to-rank, recommendation systems, grounded generation, LLM-based ranking, retrieval-augmented generation, conversational AI, or agentic AI systems.
  • Experience with offline and online evaluation, including relevance metrics, A/B experimentation, human evaluation, model diagnostics, and production quality monitoring.
  • Experience working with large-scale datasets, production ML pipelines, distributed training or inference systems, and cross-functional engineering teams.
  • Demonstrated ability to lead ambiguous technical projects as a senior individual contributor and influence product, engineering, and science direction.
  • Experience with production-scale LLM systems, agent frameworks, search engines, ranking systems, or retrieval-augmented generation systems.
  • Experience improving multi-turn AI assistant or agent experiences in real products.
  • Experience with tool-using agents, planning systems, memory, personalization, source ranking, or enterprise search.
  • Experience building evaluation frameworks for factuality, grounding, hallucination, relevance, safety,

Other signals

  • large-scale content platforms
  • improving how AI systems retrieve information, reason over context, maintain multi-turn conversations, use tools, rank candidate responses or actions, and produce reliable outputs grounded in trusted data
  • tuning and improving models at scale
  • lead complex scientific workstreams
  • influence product direction
  • partner closely with engineering, research, and product teams