Member of Technical Staff - Post-Training and RL

SpaceXAI; Palo Alto (CA); On-site; USD 180,000 - 600,000; Full time

Benefits offered by this job

Equity

Medical coverage

Dental coverage

Vision coverage

401(k)

Disability Insurance

Life Insurance

Perks and discounts

Job summary

xAI is seeking a bold engineer to tackle the most critical post-training and reinforcement learning challenges, including reward modeling and preference optimization (RLHF/DPO). The role focuses on enhancing reasoning, truthfulness, and real-world capabilities of our AI systems.

You will join a hands-on, meritocratic team that values initiative, high-quality work, and clear communication, with a strong emphasis on engineering excellence and knowledge sharing.

Qualifications

• Belief that truth-seeking AI is critical to progress.
• Passion for building useful models through post-training and RL.
• Power user of AI models; push boundaries of RL and alignment.
• Experience with RLHF/DPO is a plus but not required.
• Prides in work and thrives in meritocratic environments.

Responsibilities

• Tackle the most critical post-training and RL challenges at any given time.
• Work on reward modeling and preference optimization (RLHF/DPO).
• Improve reasoning, truthfulness, and real-world capabilities of models.

Skills

Truth-seeking AI

Post-training & RL techniques

AI model proficiency

Meritocratic mindset

Strong communication skills

Job description

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 ROLE:

• You will work on the most critical post-training and reinforcement learning challenges at any given time — including reward modeling, preference optimization (RLHF/DPO), and RL for improving reasoning, truthfulness, and real-world capabilities.
• You will get clarity on your first project before an offer.

BASIC QUALIFICATIONS:

• You believe truth-seeking AI is the most important and challenging problem.
• You are obsessed about building incredibly useful models through post-training and RL techniques.
• You are a power user of AI models and eager to push the boundaries of what’s possible with reinforcement learning and alignment methods.
• If you previously worked on post-training, RLHF, or trained models used by millions of people it’s a big plus, but relevant experience is not required.
• You take pride in your work and thrive in meritocratic environments.

COMPENSATION AND BENEFITS:

$180,000 - $600,000 USD

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. For details on data processing, view our Recruitment Privacy Notice.