Senior Systems Engineer, Concurrency & Runtime

Roblox; San Mateo (CA); On-site; USD 197,000 - 243,000; Full time

Job summary

Roblox is seeking a Principal Engineer for the Game Engine Runtime concurrency system based in San Mateo, CA. You will own the task scheduler, fiber runtime, and async APIs across the engine, tackle 3K-player server scalability, and debug production issues across PC, Mac, mobile and console.

You will collaborate with multiple engine teams, improve performance, and enhance ergonomics, testability, and debuggability of concurrent code. The role includes eligibility for equity and benefits.

Qualifications

• 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.

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.

Skills

C++17+

Multithreading

Performance profiling

Cross-platform development

Tools

MicroProfiler

Job description

Roblox is seeking a Principal Engineer for the Game Engine Runtime concurrency system based in San Mateo, CA. You will own the task scheduler, fiber runtime, and async APIs across the engine, tackle 3K-player server scalability, and debug production issues across PC, Mac, mobile and console.

You will collaborate with multiple engine teams, improve performance, and enhance ergonomics, testability, and debuggability of concurrent code. The role includes eligibility for equity and benefits.