Principal Applied Scientist

Core Search and AI team (Bing) is looking for people who want to build the next generation of search using advanced AI technologies especially large language models at scale. We are responsible for the largest machine learning models at Microsoft by volume and take pride in being the first in the world to solve many practical AI at Scale challenges. Our work spans a very large scope of scenarios including delivering high quality search results from a massive document corpus query and document understanding retrieval and reranking model for search results optimization as well as AI search grounding etc.

We areseekinga highly motivated and experienced Principal Applied Scientist with solid machine learning expertise and can adopt state-of-art AI technologies to improve the relevance for the next generation of search.

As a team we leverage the diverse backgrounds and experiences of passionate engineers scientists and program managers to help us realize our goal of making the world smarter and more productive. We believe great products are built by inclusive teams of customer-obsessed individuals who trust each other and work together closely. We collaborate regularly across the company to find technological breakthroughs from groups like Microsoft Research to infusing AI into the rest of Microsoft products like Office and Azure.

Microsofts mission is to empower every person and every organization on the planet to achieve more and we believe that artificial intelligence will play a critical role in accomplishing that mission. The Core Search and AI team is the leading applied machine learning team at Microsoft responsible for delivering the highest-quality search experience to over 500M monthly active users around the world in Microsofts search engine Bing and other dependent search engines such as Yahoo DuckDuckGo and new startups like Neeva.

Starting January 26 2026 AI Experience (AIX) employees who live within a 50- mile commute of a designated Microsoft office in the U.S. or 25-mile commute of a non-U.S. country-specific location are expected to work from the office at least four days per week. This expectation is subject to local law and may vary by jurisdiction.

• You will lead one or more big initiatives leveraging your expertise across a broad research landscape including advanced research methodologies and applied techniques. Youll gain deep knowledge of a service platform or domain and drive product opportunities by sharing emerging industry trends and applied technologies.
• You will review business requirements and incorporate research insights to meet strategic goals. Youll provide directions on the types of data and machine learning model strategies needed to solve complex problems and apply deep subjectmatter expertise to drive measurable business impact.
• You will support the onboarding of new team members and help develop academic collaborators into effective contributors within multidisciplinary teams. Youll identify promising research talent engage with the academic community and strengthen Microsofts longterm recruiting pipeline.
• You will advance LLM posttraining and alignment techniques by designing implementing and evaluating novel methods that improve reasoning quality safety controllability and factual grounding across largescale models.
• You will drive and develop nextgeneration search capabilities by building and optimizing retrieval ranking and relevance systems that integrate deeply with LLMpowered experiences.
• You will architect and refine RAG pipelines that enhance retrieval fidelity reduce hallucinations and deliver more contextaware useraligned responses in production environments.
• You will translate research into production by running experiments analyzing results and collaborating with engineering partners to deploy scalable reliable model improvements.
• You will drive scientific rigor through hypothesisdriven experimentation reproducible methodologies and clear documentation of findings insights and model behaviors.
• You will drive collaborate across disciplinesincluding research engineering product and designto shape longterm strategy for search alignment and retrievalaugmented systems.
• You will contribute to a culture of innovation by sharing learnings mentoring peers and participating in internal research discussions reviews and technical deep dives.

Required Qualifications:

• Bachelors Degree in Statistics Econometrics Computer Science Electrical or Computer Engineering or related field AND 8 years related experience (e.g. statistics predictive analytics research)
  • OR Masters Degree in Statistics Econometrics Computer Science Electrical or Computer Engineering or related field AND 6 years related experience (e.g. statistics predictive analytics research)
  • OR Doctorate in Statistics Econometrics Computer Science Electrical or Computer Engineering or related field AND 5 years related experience (e.g. statistics predictive analytics research)
  • OR equivalent experience.

Preferred Qualifications:

• Masters Degree in Statistics Econometrics Computer Science Electrical or Computer Engineering or related field AND 12 years related experience (e.g. statistics predictive analytics research)
  • OR Doctorate in Statistics Econometrics Computer Science Electrical or Computer Engineering or related field AND 8 years related experience (e.g. statistics predictive analytics research)
  • OR equivalent experience.
• 6 years of experience coding in Python C C# C or Java.
• 6 year of industry experience applying Machine Learning techniques.
• Experience building and improving large scale Machine Learning system for search ads and recommendation adopting LLM.
• Research background on Machine Learning LLM and NLP.
• Proficient problemsolver:ability to identify and solve problems that the world has not solved before.

#AIX

Applied Sciences IC6 - The typical base pay range for this role across the U.S. is USD $165600 - $296400 per year. There is a different range applicable to specific work locations within the San Francisco Bay area and New York City metropolitan area and the base pay range for this role in those locations is USD $220800 - $331200 per year.

Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here:
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.

Required Experience:

IC