Software Engineer, Sandbox Service

xAI|18 Dec 2025

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Listed location: London, England, United Kingdom

Work arrangement: onsite. A remote label does not confirm worldwide eligibility or visa sponsorship.

Read the employer’s description for qualifications, compensation and work eligibility. Confirm the position is still open on the application page.

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Job Description

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.

SOFTWARE ENGINEER, SANDBOX SERVICE

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:

Experience with Rust, C++, or Go
Experience with virtualisation and containerisation technologies (e.g., cgroups, KVM, gVisor, QEMU)

PREFERRED SKILLS AND EXPERIENCE:

Solid knowledge of the networking stack
Familiarity with Python
Deep experience with either Linux or Windows systems (familiarity with both is a strong plus)

COMPENSATION AND BENEFITS:

£107,000 - £262,000 GBP

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.

SpaceXSI is an equal opportunity employer. For details on data processing, view our Recruitment Privacy Notice.

Skills mentioned

PythonGoRustReinforcement LearningC++

Frequently asked questions

Is the Software Engineer, Sandbox Service position at xAI remote?

The Software Engineer, Sandbox Service role at xAI does not have a confirmed remote arrangement in our data. Check the employer description for its work location.

What type of employment is the Software Engineer, Sandbox Service role?

xAI is hiring for a full-time Software Engineer, Sandbox Service position.

Which skills are mentioned for the Software Engineer, Sandbox Service job at xAI?

Detected skill labels include Python, Go, Rust, Reinforcement Learning, C++. Check the employer description to distinguish required skills from preferred experience.