Senior Software Engineer, Foundation & Luau Platform

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 Foundation and Luau Platform team builds the shared platform that Roblox's user interface runs on. Our UI is written in Luau, Roblox's scripting language, using React-style frameworks. We own the core pieces that product teams across Roblox rely on: a component library used across Roblox's apps and tools, server-driven UI, the core app frame and navigation, and the frameworks and libraries underneath them. Our goal is to make that platform fast, consistent, and reliable for the engineers who build on it. As a Senior Software Engineer, you will help shape and build it, working across systems, platforms, and infrastructure. You Will • Design and build the frameworks and APIs that Roblox's UI is built on, including layout and navigation systems, server-driven UI, and a shared component library • Build and evolve the core systems beneath the UI, such as navigation, routing, state management, and data flow, so features load quickly and behave consistently • Drive startup performance, transition smoothness, and layout stability across the client on phones, tablets, and desktop, using traces and telemetry to set measurable quality bars • Roll out platform changes safely at scale, using feature flags, staged rollouts, and side-by-side validation of old and new implementations, with fast rollback when needed • Drive adoption of the platform across Roblox by partnering with product, design, and feature engineering teams to guide them onto our frameworks and components, and turning their feedback into a better platform • Raise the quality bar through thoughtful code review, strong test coverage, and clear documentation, and mentor other engineers You Have • 4+ years of professional experience building and shipping client applications, ideally on mobile (iOS, Android) or desktop, with a strong foundation in application architecture • Strong hands-on experience with React and a solid understanding of how it works, including its component model, state management, and rendering behavior, ideally in an application setting such as React Native rather than purely web • Experience designing shared frameworks, UI platforms, or core libraries that other engineers build on • A solid understanding of client rendering and layout performance across multiple screen sizes, form factors, and orientations • Strong debugging and profiling skills, with experience diagnosing performance issues such as slow startup, visual stutter, and memory pressure • Experience with feature flagging, staged rollouts, and experiment-driven launches • Strong written and verbal communication skills, and the ability to align multiple teams around a technical plan • Comfort working in a large, evolving codebase and migrating legacy code incrementally Bonus Points • Experience with Luau or Lua • Experience with React Navigation or comparable routing libraries • Experience with native mobile development on iOS or Android • Experience with server-driven UI or dynamic UI delivery systems • Ex