Principal Machine Learning Engineer

Overview

As a Principal Machine Learning Engineer, you will work on the Data Labeling and classification on large scale multi modal Copilot data part of the Microsoft AI (MAI) organization. We're looking for a hands-on ML engineer to prototype and productionize complex classification flows on real production logs, operate prompted classifiers at scale (ad hoc and scheduled), and build secure, compliant data-labeling pipelines. We're looking for someone with experience in data pipelines, data science, and machine learning, as well as a strong communicator and great teammate. The right candidate takes the initiative and enjoys building world-class consumer experiences and products in a fast-paced environment.

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, MAI employees are expected to work from a designated Microsoft office at least four days a week if they live within 50 miles (U.S.) or 25 miles (non-U.S., country-specific) of that location. This expectation is subject to local law and may vary by jurisdiction.

Responsibilities

• Build evaluation loops (precision/recall, calibration, drift, human-in-the-loop) and publish dashboards/SLOs.
• Generalize machine learning (ML) solutions into repeatable frameworks.
• Operationalize prompted classifiers at scale (batch & streaming), including orchestration, autoscaling, monitoring, and cost guardrails.
• Conduct thorough review of data analysis and techniques used to summarize the process review and highlight areas that have been missed or need re-examining.
• Collaborate cross-functionally with DS, Security, and Platform to define schemas, access patterns, and governance.
• Independently write efficient, readable, extensible code and model pipelines.
• Commit to a customer-oriented focus by acknowledging customer needs and perspectives, validating customer perspectives, focusing on broader customer context, and serving as a trusted advisor.

Qualifications

Required Qualifications:

• Bachelor's Degree in Computer Science or related technical field AND 6+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python
  • OR equivalent experience.

Preferred Qualifications:

• 7+ years' experience writing production-quality Python or Java or Scala code.
• 5+ years' experience in distributed systems design and implementation of large scale data processing systems
• 3+ years' experience building ML data pipelines using atleast one of AML, Promptflow, Langchain or LangGraph
• Demonstrated interest in Responsible AI.
• Experience prompting, evaluating, and working with large language models.

#MicrosoftAI

Software Engineering IC5 - The typical base pay range for this role across the U.S. is USD $139,900 - $274,800 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 $188,000 - $304,200 per year.

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