Senior Sandbox Platform Security Engineer

Roblox Corporation; San Mateo (CA); On-site; USD 269,000 - 326,000; Full time

Job summary

Roblox Corporation seeks a Senior Security Software Engineer for Sandbox Platforms to design, implement, and harden process sandboxes across Linux, macOS, and Windows. You will be the last line of defense, analyzing attack surfaces and building robust containment for untrusted code.

You'll work on isolation primitives like nsjail, seccomp-bpf, namespaces, AppContainer, and related technologies, writing threat models and documenting tradeoffs for performance and compatibility.

Qualifications

• Deep, hands-on knowledge of the OS security model on at least one of Linux, macOS, or Windows, and the sandboxing primitives that platform provides.
• Strong grasp of attack surface analysis: how sandboxes are escaped and how to shrink the ways in.
• Fluency in the boundary between sandbox and host (brokers, IPC, syscall filtering, privilege separation) and how to design a minimal, well-audited interface.
• Systems programming in C, C++, or Rust; comfort at the syscall and kernel-interface level.
• Sound judgment on tradeoffs: knowing when tighter isolation is worth the cost and when it isn't.
• A security mindset: you default to least privilege and distrust every input crossing the boundary.

Responsibilities

• 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.
• 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.
• Enumerate and reduce attack surface: kernel syscall surface, broker interfaces, device access, and side channels. Assume the code inside is hostile.
• Make deliberate engineering tradeoffs between isolation strength, performance, compatibility, and maintainability, and document the reasoning.
• Write threat models, review designs, and respond to sandbox escapes and hardening findings.

Skills

Sandboxing primitives

OS security model

C/C++/Rust

Threat modeling

IPC and brokers

Kernel interface

Tools

nsjail

seccomp-bpf

Landlock

Seatbelt

AppContainer

Job description

Roblox Corporation seeks a Senior Security Software Engineer for Sandbox Platforms to design, implement, and harden process sandboxes across Linux, macOS, and Windows. You will be the last line of defense, analyzing attack surfaces and building robust containment for untrusted code.

You'll work on isolation primitives like nsjail, seccomp-bpf, namespaces, AppContainer, and related technologies, writing threat models and documenting tradeoffs for performance and compatibility.