Principal Applied Scientist

Overview

We are seeking a Principal Applied Scientist to lead the next generation of click-through-rate (CTR) for Microsoft Advertising. This is a high-impact role responsible for advancing large-scale ranking models that power Microsoft Advertising, generating billions of impressions and revenue-critical decisions daily.

You will combine deep machine learning expertise, solid engineering execution, and business intuition to modernize our prediction stack, drive model innovation, and mentor a growing team of scientists and engineers.

This role is ideal for someone who thrives in complex, high-scale systems, who brings thought leadership to ML strategy, and who raises the bar for engineering rigor, curiosity, and business-driven decision making across the team.

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.

Responsibilities

ML / Modeling Leadership

* Lead the end-to-end development of large-scale CTR and other user response signal models for Search and Display ads.

* Design, prototype, and ship cutting-edge ML architectures (deep models, multi-task, transformer-based, LLM-assisted, multimodal).

* Define long-term modeling strategy and roadmap with clear business impact.

Technical & Engineering Execution

* Modernize our current modeling pipelines, addressing critical technical debt in data flows, training pipelines, and inference systems.

* Partner closely with engineering teams to improve reliability, monitoring, and performance of distributed training and online serving.

* Introduce best practices for experiment design, ablations, feature validation, and productionization.

Business & Product Impact

* Work with PMs, monetization teams, and auction experts to translate business needs into modeling goals.

* Own model performance holistically: quality, stability, latency, and revenue impact.

* Develop frameworks to better understand advertiser value, user behavior, and marketplace dynamics.

Leadership & Mentorship

* Mentor and up-level applied scientists and ML engineers across the organization.

* Drive a culture of curiosity, deep system understanding, and high-quality scientific reasoning.

* Improve collaboration norms, documentation quality, and cross-team alignment.

Innovation & Tooling

* Leverage and influence LLM-based tooling (e.g., agents, copilots) to improve team productivity and model development velocity.

* Identify opportunities to incorporate new modeling signals, architectures, or evaluation metrics.

Qualifications

Required/minimum qualifications

* 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.

Additional or preferred qualifications

* 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.,…