Principal Applied Scientist

Microsoft • Redmond, WA

31d • Hybrid

About The Position

Copilot in the Microsoft Advertising Platform is your AI-powered companion, designed to revolutionize how advertisers create, manage, and optimize campaigns. From troubleshooting to generating high-performing creatives - text, image, and video - Copilot empowers advertisers at every step of their journey. We are a dynamic team of engineers and applied scientists, pushing the boundaries of Generative AI to deliver cutting-edge tools that drive impact at scale.
We are looking for a Principal Applied Scientist to lead the development of the Copilot Chat Assistant to help advertisers navigate every step of their journey. You will design and productionize systems that orchestrate multiple Large Language Models (LLMs) using Agentic Frameworks (e.g., Semantic Kernel) and leverages Vector Databases, Retrieval Augmented Generation (RAG), and Model Context Protocol (MCP) based tools to solve complex, multi‑step tasks. Your work will directly impact the topline revenue metrics for Microsoft Advertising.
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.
Starting January 26, 2026, Microsoft AI (MAI) 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.

Requirements

• Bachelor's 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 Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 4+ years related experience (e.g., statistics, predictive analytics, research)
• OR Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 3+ years related experience (e.g., statistics, predictive analytics, research)
• OR equivalent experience.

Nice To Haves

• Master's Degree in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 9+ years related experience (e.g., statistics, predictive analytics, research)
• OR Doctorate in Statistics, Econometrics, Computer Science, Electrical or Computer Engineering, or related field AND 6+ years related experience (e.g., statistics, predictive analytics, research)
• OR equivalent experience.
• 5+ years experience developing and deploying live production systems, as part of a product team.
• 7+ years experience developing and deploying products or systems at multiple points in the product cycle from ideation to shipping.
• Experience using LLMs, agentic frameworks, RAG, vector databases to build complex production systems.

Responsibilities

• Own the science roadmap for Copilot Chat Assistant - from ideation to reliable, safe production launches.
• Design multi‑agent reasoning systems that blend LLM orchestration, tool use, and state management for long‑running tasks.
• Build robust retrieval pipelines (RAG + vector stores) for precise, grounded answers across advertiser and campaign domains.
• Advance prompt/program design (planning, decomposition, self‑reflection, evaluation) to boost accuracy, latency, and cost efficiency.
• Ship real features with engineering partners: telemetry, online evaluations/A‑B tests, guardrails, red‑teaming, and quality bars.
• Mentor and multiply: guide applied scientists and engineers, set best practices, and raise the bar for scientific rigor.
• Measure impact: define success metrics, instrument experiments, and iterate quickly based on data and customer feedback.

What This Job Offers

• Job Type: Full-time
• Career Level: Principal
• Number of Employees: 5,001-10,000 employees