Senior Security Software Engineer, Sandbox Platforms

<div class="content-intro"><p><span style="font-weight: 400;">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.&nbsp;</span></p> <p><span style="font-weight: 400;">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.</span><strong> </strong><span style="font-weight: 400;">We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there.&nbsp;</span></p> <p><span style="font-weight: 400;">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.</span></p></div><h2><span style="font-size: 12pt;">About the role</span></h2> <p>We build the isolation layers that contain untrusted and semi-trusted code. You will design, build, and harden process sandboxes across one or more of Linux, macOS, and Windows, the last line of defense when something inside goes wrong. This is a deep systems role for someone who thinks in terms of attack surface, threat models, and the exact boundary between trusted and untrusted.</p> <h2><span style="font-size: 12pt;">You Will:</span></h2> <ul> <li>Design and implement sandboxes using platform primitives: nsjail, seccomp-bpf, namespaces, cgroups, and Landlock on Linux; the Seatbelt (sandbox_init / SBPL) and related mechanisms on macOS; AppContainer, job objects, restricted tokens, and integrity levels on Windows.</li> <li>Define and lock down every communication path in and out of the sandbox: syscalls, IPC, shared memory, file descriptors, sockets, brokers, and minimize what each one exposes.</li> <li>Enumerate and reduce attack surface: kernel syscall surface, broker interfaces, device access, and side channels. Assume the code inside is hostile.</li> <li>Make deliberate engineering tradeoffs between isolation strength, performance, compatibility, and maintainability, and document the reasoning.</li> <li>Write threat models, review designs, and respond to sandbox escapes and hardening findings.</li> </ul> <h2><span style="font-size: 12pt;">You Have:</span></h2> <ul> <li>Deep, hands-on knowledge of the OS security model on <strong>at least one</strong> of Linux, macOS, or Windows, and the sandboxing primitives tha