Member of Technical Staff - Sandbox Service

SpaceXSI; Greater London; On-site; GBP 120,000 - 180,000; Full time

Benefits offered by this job

Equity

Healthcare and dental coverage

Cash plan

Income protection

Life insurance

Employee discounts and perks

Job summary

SpaceXSI in London is seeking a Member of Technical Staff for the Sandbox Service to design, build, and operate a secure, scalable system granting models controlled access to computational environments. You will work across containers, VMs, and large clusters to support real-time code execution and testing of tools.

Applicants should have deep Rust/C++/Go knowledge, familiarity with Python, and strong experience with Linux or Windows systems, virtualization, and networking.

Qualifications

• Expert knowledge of Rust, C++ or Go.
• Familiarity with Python.
• Experience with Linux or Windows systems.
• Experience with virtualization and containerization technologies.
• Strong understanding of networking.

Responsibilities

• Build and maintain a secure, scalable Sandbox service infrastructure.
• Enable models to access computational environments reliably.
• Collaborate across teams to optimize performance and security.

Skills

Rust

C++

Go

Python

Linux

Windows

Virtualisation

Containerisation

Networking

Job description

Member of Technical Staff - Sandbox Service

London, England, United Kingdom

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of making life multiplanetary and expanding consciousness to the stars.
SpaceXSI is building Super Intelligence to help humanity understand the universe. Our teams are building the full Super Intelligence stack: from our Colossus supercomputers, to Grok models, to our suite of applications, including Grok Bot, Grok Build, Grok Imagine, Grok Voice, and X. We're creating a powerful flywheel where more compute trains better models, better models power more useful products, and what we learn from people using those products shapes what we build next.

ABOUT THE ROLE:

The Sandbox service team at SpaceXSI builds and maintains a secure, scalable system that gives our models safe, controlled access to computational environments. This infrastructure powers critical workloads across training and product, enabling models to run code, build software, interact with tools, and even control applications with user interfaces. We provision containers and virtual machines on large-scale clusters, granting models interactive control over these remote environments. Our work spans the full stack: from orchestrating massive jobs and resource scheduling at the cluster level, to fine-tuning filesystem performance on nodes. The Sandbox service enables Grok to safely run and test code in real-time for user queries, and supports reinforcement learning in training, where models interactively explore tools ranging from compilers to productivity apps.

BASIC QUALIFICATIONS:

• Expert knowledge of Rust, C++ or Go
• Familiarity with Python
• Deep experience with either Linux or Windows systems (familiarity with both is a strong plus)
• Experience with virtualisation and containerisation technologies (e.g., cgroups, KVM, gVisor, QEMU)
• Solid knowledge of the networking stack

COMPENSATION AND BENEFITS:

Base salary is just one part of our total rewards package at SpaceXSI, which also includes equity, comprehensive healthcare and dental coverage, cash plan, income protection, life insurance, and various other discounts and perks.