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Palo Alto, United States

Member of Technical Staff - Post-Training and RL

SpaceXAI · Palo Alto · United States

$180,000–$600,000 per year

Posted: 4/29/2026 · Last checked: 10/12/2026

Job description

Quoted in full from SpaceXAI's job posting. Gavroche does not edit it.

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 understand the universe and help expand humanity’s knowledge and capabilities. We work across the full Super Intelligence stack: compute (Colossus supercomputers), models (Grok), and applications (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.

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 SpaceXAI, 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.

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

New openings in Palo Alto, by week

  1. 7/20/2026 27
  2. 7/27/2026 13
  3. 8/3/2026 33
  4. 8/10/2026 20
  5. 8/17/2026 21
  6. 8/24/2026 28
  7. 8/31/2026 25
  8. 9/7/2026 21
  9. 9/14/2026 27
  10. 9/21/2026 40
  11. 9/28/2026 46
  12. 10/5/2026 35
  13. 10/12/2026 1

337 openings over 12 weeks, by the week they were published.

Other roles at SpaceXAI

261 open, including roles outside the United States.