AI Engineer & Researcher - Post-training

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. Engineers are encouraged to work across multiple areas of the company, and as a result, all engineers and researchers share the title "Member of Technical Staff." 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. xAI does not have recruiters. Every application is reviewed directly by a technical member of the team. Tech Stack Python JAX Rust Location The role is based in the Bay Area [San Francisco and Palo Alto]. Candidates are expected to be located near the Bay Area or open to relocation. Focus Designing and implementing evaluations for new capabilities. Creating new and enhancing existing human and synthetic data generation methods and pipelines. Experimenting with novel fine-tuning and reinforcement learning techniques. Optimizing training data quality and data mixture to improve evaluation metrics. Innovating new ideas that bring us closer to our goal: Developing AI systems that can accurately understand the universe and create new knowledge. Ideal Experiences Expert in ML and fine-tuning large language models. Experience in developing and managing large-scale machine learning systems. Experience in connecting machine learning model behavior to data distribution and data quality. Familiar with the latest prompting and inference-time search techniques. 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: Coding assessment in a language of your choice. Post-Training Technical Session (2): This session will be testing your ability to formulate, design and solve concrete problems in post-training. It can be research or engineering, depending on background/experience.  Meet the Team: Present your past exceptional work and your vision with xAI to a small audience. Our goal is to finish the main process within one week. We don’t rely on recruiters for assessments. Every application is reviewed by a member of our technical team. All interviews will be conducted via Google Meet.

xAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge.