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Job Details
Posted date: Jan 13, 2026
There have been 2308 jobs posted with the title of Principal Software Engineer all time at Microsoft.There have been 2308 Principal Software Engineer jobs posted in the last month.
Category: Software Engineering
Location: Redmond, WA
Estimated salary: $222,050
Range: $139,900 - $304,200
Employment type: Full-Time
Work location type: 4 days / week in-office
Role: Individual Contributor
Description
OverviewWe are looking for an experienced Software Engineer to join the Ads Engineering team and help advance the core capabilities of our Ads serving stack. This system powers advertisements across a range of Microsoft services, including Bing Search, MSN, Start.com, and shopping experiences in the Edge browser. Our serving stack is a high-scale, low-latency, geo-distributed system with numerous components—including large-scale machine learning inference for ad ranking, real-time bidding infrastructure, and other subsystems supporting diverse ad scenarios.
This role offers an exciting opportunity to contribute to the innovation and evolution of a system operating at an exceptional scale and speed. You’ll face a wide variety of technical challenges: from designing new features and optimizing performance down to the millisecond, to building scalable infrastructure for containerized services. You’ll work alongside a passionate, world-class engineering team, own major feature areas, and collaborate globally. If you thrive on solving complex technical problems in a dynamic environment, this is the opportunity for you.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
Design and develop large-scale, distributed systems—including CPU and GPU ranking platforms—to support real-time processing of millions of ad requests per second with high efficiency, extensibility, diagnosability, reliability, and maintainability.Lead architecture discussions, create technical design documents, and drive end-to-end solution planning—identifying system dependencies, performance optimizations, and security/compliance requirements across interconnected services.Implement features and enhancements with a focus on code quality, maintainability, and scalability; conduct thorough code reviews to uphold Microsoft engineering standards and ensure solutions are production-ready.Serve as a Designated Responsible Individual (DRI) for live-site operations on a rotational on-call basis, proactively identifying, resolving, and escalating service degradations or interruptions to maintain high availability.Guide testing strategies and quality assurance plans, including unit tests, automation, and telemetry-based diagnostics to validate assumptions, ensure reliability, and drive continuous improvement in service performance.Mentor engineers on software engineering best practices, reusable patterns, and tooling; lead efforts to improve performance through debugging, refactoring, experimentation, and instrumentation at scale.Drive engineering excellence through compliance with global and local regulations, investment in modern tools and trends, and close collaboration with partner teams to deliver secure, performant, and customer-aligned ad-serving solutions.
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#, Python OR equivalent experience.
Preferred Qualifications:
Master's Degree in Computer Science or related technical field AND 8+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or PythonOR Bachelor's Degree in Computer Science or related technical field AND 12+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or PythonOR equivalent experience.Proven experience in designing, implementing, and validating deep learning systems for real-time online inference.
Solid expertise in optimizing machine learning models for GPUs, including development of custom CUDA kernels for performance-critical workloads.Hands-on experience in designing, implementing, and scaling large-scale, distributed online systems with a deep understanding of system architecture is a must.Proven ability to profile, analyze, and optimize performance and capacity of native C++ systems in complex, high-throughput environments.
#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:
https://careers.microsoft.com/us/en/us-corporate-pay
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.
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