Principal Software Engineer (Core Services)

Join Roblox as a Principal Software Engineer on the Core Services team, where you will build and evolve foundational services and software infrastructure. You will solve complex problems related to distributed systems, concurrency, memory management, API design, and developer experience. Your work will improve the performance and reliability of our C# ecosystem, expand our Rust infrastructure, and develop shared components and interoperability patterns across both languages. This role combines hands-on systems engineering with technical leadership, and you will work with service owners and infrastructure partners to turn complex platform capabilities into reliable, usable building blocks.

- Experience building and evolving reusable libraries, SDKs, frameworks, or runtime infrastructure adopted by multiple teams
- Demonstrated technical leadership: framing ambiguous problems, explaining tradeoffs, aligning stakeholders, mentoring engineers, and driving cross-team execution
- Experience designing stable APIs and managing compatibility, versioning, dependencies, and adoption across dependent systems
- Deep production experience in C#/.NET or Rust, with the ability and interest to work effectively across both ecosystems
- A bachelor’s degree in Computer Science or a related field, or equivalent experience
- A track record of diagnosing complex production problems and delivering measurable performance or reliability improvements
- Strong fundamentals in concurrency, asynchronous programming, memory management, networking, and distributed systems
- .NET runtime internals, GC and allocation optimization, thread-pool behavior, or production profiling
- Rust ownership and lifetimes, async runtimes, concurrent data structures, or performance-sensitive library design
- Managed/native interoperability, FFI, native memory diagnostics, or cross-platform packaging
- Contract-driven code generation, serialization, compatibility testing, or large-scale framework migrations
- Automated validation and rollout of shared dependencies across a service fleet