Software Engineer - Reasoning Infrastructure

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 engineers and researchers are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates.

About the Role

xAI is seeking experienced software engineers to build the software infrastructure that enables our models to use tools effectively and solve real-world problems. You will work closely with research teams and directly support advances in reinforcement learning, agentic AI, and model evaluation.

Focus

• Develop infrastructure for reinforcement learning training environments, including building and maintaining high-performance secured sandboxed execution environments


• Enhance observability and optimize resource utilization and performance for our distributed computing infrastructure


• Collaborate with research teams to build scalable, production-grade systems for AI experimentation

Ideal Experiences

• Experience with high-performance sandboxed code execution environments


• Experience with Kubernetes, containerization/virtualization, distributed systems, high-performance computing


• Proficiency with Python, async/concurrent programming, Rust


• Care deeply about code quality, performance, testing


• Comfortable working closely with researchers

Tech Stack

• Python / Rust


• Kubernetes


• Spark

Location

The role is based in the Bay Area [San Francisco and Palo Alto]. Candidates are expected to be located in the Bay Area or open to relocation.

Interview Process

After submitting your application, the team reviews your CV and statement of exceptional work. If your application passes this stage, you will be invited to a 15 minute interview (“phone interview”) during which a member of our team will ask some basic questions. If you clear the initial phone interview, you will enter the main process, which consists of four technical interviews:

1. Coding assessment in a language of your choice.


2. Systems hands-on: Demonstrate practical skills in a live problem-solving session.


3. Project deep-dive: Present your past exceptional work to a small audience.


4. Meet and greet with the wider team.

Our goal is to finish the main process within one week. All interviews will be conducted via Google Meet.

Annual Salary Range

$180,000 - $440,000 USD

xAI is an equal opportunity employer and does not unlawfully discriminate based on race, color, religion, ethnicity, ancestry, national origin, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender, gender identity, gender expression, age, disability, medical conditions, genetic information, marital status, military or veteran status, or any other applicable legally protected characteristics.

Qualified applicants with arrest or conviction records will be considered for employment in accordance with all applicable federal, state, and local laws, including the San Francisco Fair Chance Ordinance, Los Angeles County Fair Chance Ordinance for Employers, and the California Fair Chance Act.

For Los Angeles County (unincorporated) Candidates:

xAI reasonably believes that criminal history may have a direct, adverse and negative relationship on the following job duties, potentially resulting in the withdrawal of a conditional offer of employment:

• Access to information technology systems and confidential information, including proprietary and trade secret information, and/or user data;


• Interacting with internal and/or external clients and colleagues; and


• Exercising sound judgment.