Principal Software Engineer, Online Ads Systems

Overview Online Advertising is one of the fastest growing businesses on the Internet today, with about $70 billion of a $600 billion advertising market already online. Search engines, web publishers, major ad networks, and ad exchanges are now serving billions of ad impressions per day and generating terabytes of user events data every day. The rapid growth of online advertising has created enormous opportunities as well as technical challenges that demand computationally intelligence and scalable algorithms. Eventually Computational Advertising has emerged as a new interdisciplinary field that involves information retrieval, data mining, machine learning, statistical modeling, optimization, linear algebra, and micro-economics, to solve challenging problems that arise in online advertising. Ads Frontdoor is at the core of this effort, working on large distributed systems with low latency and high throughput. Today, we design, develop, and operate a global ads marketplace that has a double-digit annual growth rate. This is a self-motivated and results driven environment that will unleash your potential. As a Principal Software Engineer and member of this team, you would help us build highly scalable, highly performant services which host state-of-the-art machine learning models. Your work will touch many components of our stack. 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 Work with BingAds stakeholders to determine requirements for new features to drive up Ads business. Create system design for feature requirements. Assure system meets security and compliance requirements and expectations. Creates a clear and articulated plan for testing and assuring quality of solutions. Implement the features with high efficiency, extensibility, diagnosability, reliability, and maintainability with few defects. Reviews code of product to assure it meets the team's and Microsoft’s quality standards, is reliable and accurate, and is appropriate for the scale of the product feature. Maintain operations of live service as issues arise on a rotational, on-call basis. Identifies solutions and mitigations to simple and complex issues and escalates as necessary. Acts as a Designated Responsible Individual (DRI) working on call to monitor system/product feature/service for degradation, downtime, or interruptions. Responds within Service Level Agreement (SLA) timeframe. Escalates issues to appropriate owners. Builds knowledge, shares new ideas, and shares pinpoints of engineering tool gaps to improve software developer tools to support other programs, tools, and applications to create, debug, and maintain code for product features. Contributes to the development of automation within production and deployment of a product feature. Profile and analyze distributed system performance and capacity bottlenecks. Propose and implement solutions to improve system latency and capacity to meet BingAds online serving requirements. 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 Qualification: 5+ years of experience in distributed system engineering and multi-threading programming. 5+ years of experience in machine learning and online system design, implementation and qualification. 5+ years of experience in profiling and analyzing distributed system performance and capacity bottlenecks. 5+ years of experience in Azure. Experienced in distributed system engineering and high-performance programming. #MicrosoftAI Software Engineering IC5 - The typical base pay range for this role across the U.S. is USD $142,800 - $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.