Senior Security Software Engineer, Sandbox Platforms

Roblox; Canada (KY); On-site; USD 269,000 - 326,000; Full time

Benefits offered by this job

Equity compensation

Benefits described on page

Job summary

Roblox is seeking a deep systems security engineer to design, build, and harden sandboxing across Linux, macOS, and Windows. You’ll manage isolation boundaries, control IPC and syscalls, and reduce attack surfaces while balancing performance and compatibility.

Responsibilities include threat modeling, design reviews, and rapid response to sandbox escapes. Strong C/C++/Rust systems programming and OS security expertise are required.

Qualifications

• Deep hands-on knowledge of OS security models on at least one platform (Linux, macOS, Windows).
• Strong ability to analyze attack surfaces and shrink exposure.
• Fluency at the boundary between sandbox and host, including interfaces and privilege separation.
• Experience with systems programming in C, C++, or Rust at kernel or syscall level.
• Ability to document tradeoffs between isolation strength, performance, and compatibility.

Responsibilities

• Design and implement sandboxes using platform primitives across Linux, macOS, and Windows.
• Define and lock down all communication paths in and out of the sandbox (syscalls, IPC, shared memory, files, sockets).
• Enumerate and reduce attack surface, including kernel syscall surface and broker interfaces.
• Make deliberate engineering tradeoffs between isolation strength, performance, compatibility, and maintainability.
• Write threat models, review designs, and respond to sandbox escapes and hardening findings.

Skills

OS security model knowledge

Sandboxing primitives

Systems programming

Threat modeling

Privilege separation

IPC / brokers understanding

Tools

nsjail

seccomp-bpf

Landlock

Seatbelt

AppContainer

Job description

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.

About the role

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.

You Will:

• 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.

You Have:

• 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.

Nice to have

• Experience across more than one of the three platforms.
• Kernel, hypervisor, or low‑level OS internals work.
• Fuzzing, exploit development, or red‑team experience against isolation boundaries.

For roles that are based at our headquarters in San Mateo, CA: The starting base pay for this position is as shown below. The actual base pay is dependent upon a variety of job‑related factors such as professional background, training, work experience, location, business needs and market demand. Therefore, in some circumstances, the actual salary could fall outside of this expected range. This pay range is subject to change and may be modified in the future. All full‑time employees are also eligible for equity compensation and for benefits as described on this page.

Annual Salary Range

$269,170 — $326,060 USD

Roles that are based in an office are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday (unless otherwise noted).

Roblox provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws. Roblox also provides reasonable accommodations to candidates with qualifying disabilities or religious beliefs during the recruiting process.

For US based roles only, please note the Company may not be able to employ candidates for this role who have United States work authorization related to certain U.S. visa categories, or support future H-1B sponsorship at this time.