Overview
The Microsoft Advertising Mediation Service (MMS) is the real-time auction and mediation platform that sits at the heart of Microsofts 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 Microsofts 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.
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
Technical Leadership
Own the long-range 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.
Drive cross-team technical strategy with peer principals across Microsoft Advertising - bidders, supply integrations, brand safety, identity, measurement, and billing.
Set and enforce engineering standards through design reviews, code reviews, technical RFCs, and mentorship of senior and staff-level engineers.
Identify and resolve systemic risks across reliability, latency, cost, and correctness before they reach production.
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.
Evolve the bidder adapter framework to support new supply types (display, native, video) and new integration patterns (server-side header bidding, deal-based, programmatic guaranteed).
Improve the auction subsystem - pricing, filtration (L1 brand safety, IP blocks, embargoes), bidder selection, and response shaping - with measurable revenue and quality impact.
Strengthen the experimentation framework (flights, traffic sub-groups) so PMs and data science can ship A/B tests safely at high cadence.
Improve observability of the request path: structured Event Hub logging, sampling strategies, metrics, and tracing across the bidder fan-out.
Infrastructure & Cloud
Drive Azure-native deployment and operational excellence across AKS, ACR, Azure Key Vault, Azure Blob Storage, Azure Event Hubs, and Azure AD.
Lead initiatives to reduce cost-per-request, improve cold-start and config-reload behavior, and harden cross-region failover.
Improve CI/CD on Azure DevOps, including canary, progressive rollout, and automated rollback strategies.
Org-Wide Impact
Lead initiatives that make delivery of high-quality software routine and efficient across the full SDLC - from inception and technical design through testing, deployment, and oncall.
Contribute to runbooks, deployment documentation, and oncall readiness
Lead efforts to raise the bar on incident response and institutionalize effective post-incident learning.
Leverage AI dev tools across the software development lifecycle to raise team-wide engineering productivity.
Qualifications
Required:
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:
Preferred:
Masters 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++, C#, Java, JavaScript, or Python
OR Bachelors 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 equivalent experience.
6+ years of experience building and operating latency-sensitive backend services with strict SLA requirements (P99 measured in milliseconds, five-nines availability).
Go - deep production experience, including profiling, GC tuning, concurrency patterns, and performance-sensitive code on the request hot path.
OpenRTB / programmatic advertising - hands-on experience with header bidding, real-time bidding, mediation, exchanges, SSPs/DSPs, brand safety, or identity/cookie syncing. Familiarity with Prebid Server or similar auction platforms.
Auction systems - experience designing or evolving pricing logic, bidder filtration, dynamic reserve pricing, or floor-price optimization at scale.
Kubernetes & Azure - production experience with AKS, ACR, Azure Key Vault, Azure Event Hubs, Azure Blob Storage, Azure Application Insights, and Azure DevOps; comfortable with multi-region, multi-cluster deployments.
Distributed systems - solid grasp of consistency trade-offs, fault tolerance, distributed caching, and cross-region replication patterns.
Experimentation platforms - experience designing or scaling A/B testing frameworks, feature flags, or controlled rollout systems.
Observability - experience with structured logging, high-cardinality metrics, sampling at scale, and event streaming pipelines (Event Hubs, Kafka, Kusto/ADX).
Proven record of mentoring senior engineers and driving cross-team technical initiatives to completion.
Solid problem-solving skills with a focus on reliability, observability, and system design.
#MicrosoftAI
Software Engineering IC5 - The typical base pay range for this role across the U.S. is USD $139,900 - $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.