New 
Principal Software Engineer
 Microsoft | |
 United States, Washington, Redmond | |
 Jul 18, 2025 | |
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OverviewWe are looking for an experienced Principal 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, 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.
ResponsibilitiesDesign and develop large-scale, distributed online serving systems-including CPU and GPU ranking and inferencing 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. | |