Senior 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 Senior 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.  

Starting January 26, 2026, Microsoft AI Experiences 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.

• Technical Contributions Contribute to the architecture of the MMS platform: the OpenRTB request hot path, auction engines (best-price, priority, dynamic reserve price, multi-placement), bidder adapter framework, and the experimentation/flights system. Collaborate with engineers across teams — bidders, supply integrations, brand safety, and measurement — on shared technical problems. Participate in design reviews and code reviews, and help develop and grow engineers across the team. Identify and surface technical risks across reliability, latency, cost, and correctness.
• Service & Platform Development Design and build highly scalable Go services on the MMS platform, with strict latency and availability SLAs measured in single-digit milliseconds and five nines. Extend the bidder adapter framework to support new supply types (display, native, video) and integration patterns (server-side header bidding, deal-based, programmatic guaranteed). Improve auction subsystem components — pricing, filtration (L1 brand safety, IP blocks, embargoes), bidder selection, and response shaping — with measurable revenue and quality impact. Contribute to the experimentation framework (flights, traffic sub-groups) to enable safe, high-cadence A/B tests. Improve observability of the request path: structured Event Hub logging, sampling strategies, metrics, and tracing across the bidder fan-out.
• Infrastructure & Cloud Contribute to Azure-native deployment and operational excellence across AKS, ACR, Azure Key Vault, Azure Blob Storage, Azure Event Hubs, and Azure AD. Participate in initiatives to reduce cost-per-request, improve cold-start and config-reload behavior, and harden cross-region failover. Improve CI/CD pipelines on Azure DevOps, including canary and progressive rollout strategies.
• Team Impact Help make delivery of high-quality software consistent and efficient across the SDLC — from technical design through testing, deployment, and oncall. Contribute to runbooks, deployment documentation, and oncall readiness. Participate in incident response and post-incident reviews. Leverage AI dev tools to raise personal and team-wide engineering productivity.

Required Qualifications:

• Bachelor's Degree in Computer Science or related technical field AND 4+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience.

Other Requirements:
Ability to meet Microsoft, customer and/or government security screening requirements are required for this role. These requirements include but are not limited to the following specialized security screenings:

• Microsoft Cloud Background Check: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two years thereafter.

Preferred Qualif