Principal Software Engineer (Substrate Store)
We are the Store team within Microsoft’s Substrate Storage Fabric — the core platform that powers Microsoft 365 experiences, from AI-powered Copilot innovations to Outlook and Teams. Our team focuses on API optimization, search running on Azure, and the security posture of the storage access path.
We are looking for a Principal Software Engineer (Substrate Store) to lead the modernization of Store Access. If you’re passionate about building latency-critical access APIs and high-throughput services that run on both BareMetal and Azure at a global scale, this role gives you the opportunity to shape one of Microsoft’s most strategic products.
You will lead complex architecture and implementation across teams, make high-judgment technical decisions that affect service reliability and customer trust, mentor engineers, and drive measurable engineering excellence. Operating at Principal scope, you will break hard cross-team problems, create clarity for multi-year technical outcomes, and set the conditions for your team and partner teams to deliver safely at global scale.
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.
Responsibilities
- Lead architecture, design, and implementation for Store Access modernization — latency-critical access APIs, search on Azure, and integration with the broader Substrate storage fabric and M365 dependencies.
- Drive API optimization at scale — define high-throughput, low-latency access contracts, concurrency and resource-governance models, caching, and back-pressure, balancing latency, cost, and reliability.
- Own the search-on-Azure technical direction — lead the design and scaling of search/indexing systems on Azure infrastructure, including index freshness, query performance, and cost efficiency.
- Own and broker cross-team architecture decisions across upstream and downstream dependencies, ensuring designs meet performance, scalability, resiliency, disaster-recovery, cost, security, privacy, compliance, and accessibility expectations.
- Lead by example in engineering craft — produce extensible, maintainable, well-tested, secure, performant code in C# and Rust, and review code and test code for diagnosability, reliability, maintainability, security risks, compliance, and appropriate coverage.
- Define the optics — quality metrics, telemetry, dashboards, and feedback loops that guide technical decisions, measure customer value, surface risks early (especially latency and security regressions), and improve service health.
- Apply AI-native development practices responsibly, including appropriate controls over AI-generated requirements, designs, code, tests, and operational assets; evaluate AI tools and practices that improve engineering productivity and quality.
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 Qualifications:
- Master's 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 Bachelor's 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.
- 2+ years acting as a Principal Engineer (or equivalent), with clear ownership of architecture, design decisions, and technical direction across multiple workstreams and teams.
- Committed-level proficiency in C# and/or Rust, with a proficient command of system performance, memory management, and multithreading.
- Deep knowledge in API design and optimization for high-throughput, low-latency services — concurrency control, resource governance, caching, and protocol/contract design.
- Committted understanding and knowledge in reliability, observability, safe deployment, and operational excellence, including oncall experience for systems serving millions of users.
- Proven ability to mentor engineers and influence technical direction without direct authority.
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.