Principal Software Engineer

Microsoft•Redmond, WA

About The Position

The Extensible Storage Engine (ESE) team is seeking an experienced software engineer to help shape the next generation of storage technologies powering Microsoft's largest and most critical services. ESE serves as a foundational storage platform for products including Microsoft 365, Microsoft Entra ID (Azure Active Directory), Cosmos DB, and other hyperscale cloud services, making storage efficiency, scalability, reliability, and cost optimization critical to Microsoft's future growth. As storage hardware evolves toward higher-density and lower-cost media such as QLC SSDs, SMR drives, Zoned Storage, and future storage technologies, traditional database architectures face increasing challenges around write amplification, endurance, space efficiency, and performance predictability. This role will drive engineering efforts to evolve ESE for these emerging environments through a combination of architectural innovation, performance engineering, and evaluation of technologies and design patterns from modern open-source storage engines such as RocksDB, Pebble, and WiredTiger. The successful candidate will help ensure ESE remains a world-class storage platform capable of supporting the next generation of Microsoft services while lowering infrastructure costs and improving storage efficiency across the company's cloud ecosystem. 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.

Requirements

Bachelor'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++ or C# OR equivalent experience.
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.

Nice To Haves

Master'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 Bachelor's Degree in Computer Science or related technical field AND 15+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience.
Significant experience developing database engines, storage systems, filesystems, distributed systems, or operating system components.
Solid C/C++ systems programming experience.
Deep understanding of: Database storage engines Transaction logging and recovery Buffer and cache management Concurrency control Filesystems and storage hardware Performance analysis and scalability engineering
Experience evaluating and integrating external or open source technologies into large-scale production systems.
Proven track record driving architecture across complex, cross-team initiatives.
Experience with RocksDB, Pebble, WiredTiger, LevelDB, Cassandra, MySQL/InnoDB, PostgreSQL internals, or similar storage engines.
Knowledge of LSM-tree architectures, compaction strategies, key-value stores, and write-optimized database designs.
Experience with QLC SSDs, SMR storage, Zoned Storage, NVMe, and emerging storage technologies.
Familiarity with storage efficiency techniques including write reduction, compression, deduplication, and tiered storage.
Experience benchmarking storage systems and performing workload characterization.
Background in cloud-scale databases or distributed storage platforms.

Responsibilities

Drive the design and implementation of ESE enhancements that improve scalability, performance, reliability, and storage efficiency.
Lead investigations into future storage technologies including QLC SSDs, SMR drives, Zoned Storage, and other emerging storage media.
Evaluate storage engine innovations from open-source technologies such as RocksDB, Pebble, WiredTiger, and related ecosystems, identifying opportunities to incorporate proven concepts and techniques into ESE.
Develop solutions that reduce write amplification, improve storage endurance, and optimize capacity utilization across large-scale deployments.
Advance ESE investments including log write path modernization, lock-free data structures, intelligent caching, write reduction technologies, and next-generation storage optimizations.
Partner closely with engineering teams across Microsoft 365, Microsoft Entra ID, Cosmos DB, and other ESE-dependent services to understand future storage requirements and translate them into platform capabilities.
Prototype, benchmark, and validate new storage architectures and technologies, providing data-driven recommendations for adoption.
Serve as a technical leader influencing ESE strategy, architecture, implementation, experimentation, and engineering execution across multiple product teams.