The Core Search and AI team at Microsoft is seeking a Principal Applied Scientist to enhance the next generation of search using advanced AI technologies, particularly large language models. This role involves leading initiatives that leverage machine learning expertise to improve search relevance and user experience. The team is dedicated to delivering high-quality search results to over 500 million monthly active users globally. Collaboration with diverse teams across Microsoft is essential to drive innovation and achieve strategic goals.

• Bachelor's Degree in a relevant field and 8+ years of related experience, or a Master's Degree with 6+ years, or a Doctorate with 5+ years of experience.
• 6+ years of experience coding in Python, C++, C#, C, or Java.
• 6+ years of industry experience applying Machine Learning techniques.
• Experience building and improving large scale Machine Learning systems for search, ads, and recommendations.
• Research background in Machine Learning, LLM, and NLP.

• Lead initiatives leveraging expertise across a broad research landscape.
• Review business requirements and incorporate research insights to meet strategic goals.
• Support onboarding of new team members and develop academic collaborators.
• Advance LLM post-training and alignment techniques to improve model quality.
• Drive next-generation search capabilities by optimizing retrieval and ranking systems.
• Architect and refine RAG pipelines to enhance retrieval fidelity and user alignment.
• Translate research into production by running experiments and analyzing results.
• Drive scientific rigor through hypothesis-driven experimentation and documentation.
• Collaborate across disciplines to shape long-term strategy for search systems.
• Contribute to a culture of innovation by sharing learnings and mentoring peers.

• Employees at Microsoft are often offered comprehensive, “world-class” benefits—including health and mental-wellness programs, competitive pay with bonuses and stock awards, and retirement/savings options. Time-off and flexibility are common, with generous vacation and holidays, parental and caregiver leave, and flexible work schedules, alongside learning support, employee resource groups, product discounts, and matching-gifts/volunteering programs. Specific benefits can vary by region.