SlipstreamJobs tracks this role from the company's public career site. Apply directly on the employer's site.
Salary: USD 196,750 - 243,290 / annual
Roblox is a platform where tens of millions of people explore, create, play, learn, and connect in 3D immersive digital experiences. The Game Engine team builds the systems powering the metaverse at scale, and this role is part of the Systems Runtime pod.
The Runtime pod owns foundational C++ components that power the entire Roblox engine and Studio stack, functioning as the "standard library" and execution engine for Roblox's C++ world. The team focuses on three pillars: Concurrency System (task scheduler and fiber runtime for parallelization across CPU cores), Memory System (engine memory allocator, tracking pipelines, and observability), and Profiling and Observability (MicroProfiler and telemetry pipelines).
This role centers on the Concurrency system. You will own the scheduler and fiber runtime that the rest of the engine is built on, research and implement performance work needed for 3K-player servers and genre expansion initiatives, and serve as the point of contact for other engine teams with concurrency needs. You will debug real production failures across PC, Mac, mobile, and console, and build deep intuition for how compilers, CPU architectures, and operating systems interact. A single well-designed primitive or optimization here makes hundreds of internal engineers more productive and millions of player sessions smoother.
Key responsibilities:
- Take ownership of part of the engine's Concurrency system — the task scheduler, fiber runtime, and async APIs that every other engine team builds on
- Research and implement performance improvements that unblock platform initiatives, unlocking higher fidelity and richer experiences
- Serve as a point of contact for concurrency across the org: design reviews, hard parallelism bugs, and asks from other engine teams
- Improve the ergonomics, testability, and debuggability of concurrent code across PC, Mac, mobile, and console
The role is hybrid based in San Mateo, with onsite presence Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday.
REQUIREMENTS:
Must Have:
- Strong modern C++ (C++17 or newer) in a large, complex production codebase
- Deep multithreading/concurrency experience — schedulers, thread pools, lock-free programming, atomics, memory models
- Comfort profiling and reasoning about performance at the OS/CPU level
Nice to Have:
- Game engine or real-time systems experience
- Fiber/coroutine runtimes, work-stealing or job-system schedulers
- Cross-platform low-level development (Android, iOS, console)
- Track record as the go-to expert other teams consult on a system
