Member of Technical Staff - Sandbox Service (Hiring Immediately) in London

About xAI

xAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All employees are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates.

About the team

The Sandbox service team at xAI 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.

About the role

Expect deeply technical work in a fast-moving environment. We prioritise speed and rapid iteration without compromising on reliability or performance. Ideal candidates have strong backgrounds in at least the following:

• 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

Location

This position is in-person in London, UK. We usually work from the office 5 days a week but allow for work-from-home days when required. Candidates must be willing to attend late meetings at least once a week to coordinate with the rest of our team in Palo Alto.

Interview process

After submitting your application, the team reviews your statement of exceptional work and CV. If your application passes this stage, the interview process is as follows:

• Initial technical screening during which a member of our team will ask some basic technical questions (15 minutes)
• Coding interview in either Rust / C++ / Go / Python (45 minutes)
• Distributed systems design (45 minutes)
• Final stage with founding engineer Toby Pohlen (30 minutes)

All interviews will be conducted via Google meet.

Benefits

Base salary is just one part of our total rewards package at xAI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.

xAI is an equal opportunity employer.