Principal Software Engineer

Senior • Hybrid • On-site

$163,000 - $296,400/yr

Redmond, WA

Overview

We 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.

Qualifications

Required Qualifications:

Bachelor'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#, Python
- OR equivalent experience.
8+ years experience in programming with native C++, including writing production-quality code.
8+ years experience in designing, implementing, and scaling large-scale, distributed online systems with a deep understanding of system architecture and proven ability to profile, analyze, and optimize performance and capacity of native C++ systems in complex, high-throughput environments.

Preferred Qualifications:

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 Python
- OR Master's Degree in Computer Science or related technical field AND 10+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python
- OR 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.

Software Engineering IC6 - The typical base pay range for this role across the U.S. is USD $163,000 - $296,400 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 $220,800 - $331,200 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

Microsoft will accept applications for the role until July 30, 2025.

#MicrosoftAI

Responsibilities

Design 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.

Microsoft

Microsoft is a global technology company that focuses on empowering every person and organization to achieve more. With a mission to deliver the core infrastructure and foundational technologies for Microsoft's online businesses, including Bing, MSN, Office 365, Xbox Live, Teams, OneDrive, and the Microsoft Azure platform, the company is dedicated to powering the 'Intelligent Cloud' mission. Microsoft values respect, integrity, and accountability, and fosters a culture of inclusion where employees can thrive. The company is committed to continuous improvement and collaboration to drive innovation and provide high-quality results to customers. With a diverse and inclusive workforce, Microsoft is an equal opportunity employer.