Principal Software Engineer

The Microsoft Advertising Mediation Service (MMS) is the real-time auction and mediation platform that sits at the heart of Microsoft's advertising stack. Built on Go and derived from Prebid Server, MMS processes OpenRTB traffic at global scale across multiple Azure regions, running header-bidding auctions, executing bidder filtration, applying dynamic reserve pricing, and powering experimentation across Microsoft's owned-and-operated and third-party supply (Outlook, MSN, Xandr, LinkedIn, MSAN, and more). We are looking for a Principal Software Engineer to set the technical direction for MMS as it scales to the next order of magnitude of traffic, supply types, and auction complexity. This is a deeply technical IC role: you will own architecture decisions that span the request hot path, the experimentation framework (flights/TSGs), bidder adapter ecosystem, and the Azure-native infrastructure that runs it all. You will partner closely with engineering leads, PMs, data science, and partner teams across Microsoft Advertising to shape the roadmap, raise the engineering bar, and mentor senior engineers across the org. 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.