Principal Software Engineering, App Performance (C++)

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. 

At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. 

A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone.

The Consumer App Foundation team is looking for a Principal Software Engineer to improve Roblox client performance across our supported platforms. You’ll work primarily in cross-platform C++ Roblox game engine code, partnering with teams across the company to identify bottlenecks, ship measurable improvements, and prevent regressions over time.

Our team owns the end-to-end performance of Roblox. We tackle the platform’s most difficult technical constraints—from speed and responsiveness to efficiency and stability —ensuring a high-performance experience across all of our devices and platforms: mobile, desktop, and console.

You will:

• Conduct research, create and drive execution of roadmaps aimed to improve efficiency of Roblox on target platforms


• Design novel solutions to optimize performance and computing resources usage of Roblox client app.


• Profile and diagnose real-world performance on iOS or Android to identify bottlenecks, validate wins, and prevent regressions using platform tooling.


• Build and productionize repeatable benchmarks/experiments, CI/CD automation to catch regressions early, dashboards/alerts with actionable signals.


• Work with stakeholders across Engineering, Product, and Design to align on priorities, tradeoffs, and rollout plans; ensure performance improvements support the user experience.


• Deliver improvements and guardrails that scale across mobile, desktop, and console, with informed tradeoffs for mobile constraints.

You have:

• 10+ years of experience: working in C++ with a track record of writing high-quality, performant code in large and complex codebases.


• Comfort with ambiguity: able to dive into unfamiliar codebases, unblock yourself, and take projects from greenfield/MVP → production-grade.


• Mobile performance expertise: hands-on experience improving performance on mobile platforms (iOS and/or Android), including on-device profiling to find and measure opportunities.


• Systems thinking: ability to build systems that work and keep on working reliably (measurement, monitoring, regression prevention).