Principal Applied Scientist

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

Principal Applied Scientist focused on improving Copilot's search and retrieval capabilities by adapting advanced vector search algorithms, improving keyword search quality with deep language understanding, designing relevance models (including LLM fine-tuning and LTR), and building evaluation pipelines. The role involves end-to-end project ownership, from ideation to shipping, and requires collaboration across engineering, product, and science teams.

What you'd actually do

  1. Drive end-to-end applied science projects: From ideation and design to implementation, experimentation, and shipping, you will lead high-impact projects that directly improve Copilot Chat, Copilot Search, and BizChat experiences. This includes identifying search and relevance gaps, formulating innovative hypotheses, and delivering scalable solutions.
  2. Innovate with scientific rigor: Invent and apply cutting-edge techniques in machine learning, natural language processing, and information retrieval to address real-world challenges at enterprise scale. You will design novel approaches for improving retrieval, ranking, query understanding, and semantic search in Copilot systems.
  3. Document, share, and amplify learnings: Promote a culture of transparency and innovation by capturing experimental results, documenting methodology, and publishing internal learnings. You’ll drive knowledge sharing that enables broader impact across the organization.
  4. Translate business goals into scientific strategy: Partner closely with product and business stakeholders to align team efforts with high-priority objectives. You will translate ambiguous product requirements into clear, data-driven, and technically feasible directions.
  5. Collaborate across organizations and time zones: Work cross-functionally with platform engineering teams, peer science orgs, and product managers to ensure alignment, resolve dependencies, and unblock progress. You’ll be a key bridge between applied science innovation and product delivery.

Skills

Required

  • Bachelor's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 8+ years related experience OR Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 6+ years related experience OR Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 5+ years related experience OR equivalent experience.
  • 8+ years of industrial programming experience in modern languages such as Python, Java, C++, or C#, including production-level ML pipelines.
  • Demonstrated expertise in data analysis at scale, including working with logs, telemetry, and large datasets to uncover behavioral patterns, build evaluation datasets, and derive insights.
  • Familiarity with modern machine learning and deep learning frameworks such as PyTorch, TensorFlow, scikit-learn, and Hugging Face Transformers.
  • Proven ability to collaborate across engineering, product, and science organizations and to communicate technical details clearly to both technical and non-technical stakeholders.

Nice to have

  • Bachelor's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 8+ years related experience OR Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 8+ years related experience OR Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 8+ years related experience OR equivalent experience.

What the JD emphasized

  • enterprise-scale semantic retrieval
  • LLM fine-tuning
  • learning-to-rank (LTR)
  • robust evaluation pipelines
  • online A/B experimentation
  • AI-powered search experiences
  • end-to-end applied science projects
  • shipping
  • search and relevance gaps
  • scalable solutions
  • machine learning
  • natural language processing
  • information retrieval
  • retrieval
  • ranking
  • query understanding
  • semantic search
  • Copilot systems
  • experimental results
  • methodology
  • internal learnings
  • business goals
  • scientific strategy
  • product and business stakeholders
  • ambiguous product requirements
  • data-driven
  • technically feasible directions
  • engineering, product, and science organizations
  • applied science innovation
  • product delivery

Other signals

  • delivering mission-critical innovations
  • enterprise-scale semantic retrieval
  • improving search quality through deep language understanding
  • designing and training relevance models
  • LLM fine-tuning
  • learning-to-rank (LTR)
  • building robust evaluation pipelines
  • online A/B experimentation
  • next generation of AI-powered search experiences
  • applied science projects
  • shipping
  • identifying search and relevance gaps
  • formulating innovative hypotheses
  • delivering scalable solutions
  • invent and apply cutting-edge techniques in machine learning, natural language processing, and information retrieval
  • improving retrieval, ranking, query understanding, and semantic search
  • documenting methodology
  • publishing internal learnings
  • translate business goals into scientific strategy
  • partner closely with product and business stakeholders
  • translate ambiguous product requirements into clear, data-driven, and technically feasible directions
  • collaborate across engineering, product, and science organizations
  • bridge between applied science innovation and product delivery