Principal Software Engineer, Ads Systems - Microsoft

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.

• 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.