Principal Applied Scientist

Overview Security represents the most critical priorities for our customers in a world awash in digital threats, regulatory scrutiny, and estate complexity. Microsoft Security aspires to make the world a safer place for all. We want to reshape security and empower every user, customer, and developer with a security cloud that protects them with end to end, simplified solutions. The Microsoft Security organization accelerates Microsoft’s mission and bold ambitions to ensure that our company and industry is securing digital technology platforms, devices, and clouds in our customers’ heterogeneous environments, as well as ensuring the security of our own internal estate. The CogAgents Research team builds intelligent, agentic systems for red teaming—autonomous agents that probe, stress-test, and uncover vulnerabilities in systems at scale. We apply deep learning, large language models, and graph-based models to develop advanced red teaming capabilities for our products, with a focus on agent design, rigorous evaluation, and continuously improving quality and performance. We are looking for a Principal Applied Scientist to lead the design, evaluation, and productization of red teaming agents. In this role, you will translate complex safety and security challenges into rigorous, data-driven solutions, design agents that identify and exploit weaknesses across systems and applications, and build robust evaluation frameworks that measure attack success, coverage, and overall effectiveness. You will use advanced machine learning techniques to systematically improve agent performance, set a high technical bar, and partner closely with product, engineering, and safety teams to deliver measurable impact. This role requires deep applied machine learning expertise, strong experience in agent design and evaluation, and a focus on turning research into real-world capabilities. We invest in our team's health and culture as key drivers of delivering great outcomes for our customers and partners. 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. Responsibilities • Design and build autonomous red-team systems and agents that discover, exploit, and report vulnerabilities in apps and digital infrastructure at scale. • Develop agentic workflows leveraging coding agents, RAG, domain knowledge repositories, and tool-integrated agents to accelerate the development, evaluation, and continuous improvement of red-team agents and systems. • Design reusable data processing frameworks, canonical data models, and data contracts that accommodate evolving red teaming and business require • Lead architectural decisions across cloud data platforms, distributed compute engines, data lakes, streaming and batch processing, and analytical serving systems, balancing data freshness, correctness, performance, and cost. • Streamline red-team agent development through automated pipelines for code reviews, failure triage, root-cause analysis, and operational knowledge discovery. • Establish governance and quality guardrails for red team agents including automated testing, correctness validation, security reviews, and production-readiness checks. • Embody our culture and corporate values. Qualifications Required Qualifications: • Doctorate in Data Science, Mathematics, Statistics, Econometrics, Economics, Operations Research, Computer Science, or related field AND 3+ years data-science experience (e.g., managing structured and unstructured data, applying statistical techniques and reporting results) • OR Master's Degree in Data Science, Mathematics, Statistics, Econometrics, Economics, Operations Research, Computer Science, or related field AND 5+ years data-science experience (e.g., managing structured and unstructured data, applying statistical techniques and reporting results) • OR Bachelor's Degree in Data Science, Mathematics, Statistics, Econometrics, Economics, Operations Research, Computer Science, or related field AND 7+ years data science experience (e.g., managing structured and unstructured data, applying statistical techniques and reporting results) • OR equivalent experience. Other Requirements : Ability to meet Microsoft, customer and/or government security screening requirements are required for this role. These requirements include, but are not limited to the following specialized security screenings: • Microsoft Cloud Background Check: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two years thereafter. Preferred Qualifications: • 10+ years technical engineering experience with coding in languages including, but not limited to Scala, Python, C#, Java OR equivalent experience. • 3+ years of experience in deep learning and development of advanced AI systems and agents • Practical experience applying AI coding assistants, LLMs, and agentic workflows to software development, code modernization, testing, and engineering automation. • Experience in RAG, embeddings, semantic search, tool calling, and agent orchestration, with experience implementing appropriate security, correctness, reliability, and human oversight controls. • Demonstrated understanding of statistical analysis, time-series analytics, anomaly detection, and forecasting. • Extensive experience in data modeling, analytical data systems, and SQL-based data analysis, including translating ambiguous business requirements into actionable metrics and insights. • Expertise in architecting, building, and operating production-grade, cloud-native data platforms using Microsoft Fabric, Azure Synapse, Azure AI Foundry, Azure Machine Learning, or equivalent technologies. • Proven