Sr. Model Engineer, Post-Training & RL (AI)

Location: Palo Alto, CA, United States

Salary: $180,000–$600,000 USD per year

Company

Builds a full super-intelligence stack spanning large-scale compute, Grok models, and AI applications.

What you will do

• Work on critical post-training and reinforcement learning challenges.
• Develop reward modeling and preference optimization methods, including RLHF and DPO.
• Apply reinforcement learning to improve model reasoning, truthfulness, and real-world capabilities.
• Contribute to models and AI products used at large scale.

Requirements

• Production-quality coding experience in Python, PyTorch, JAX, Rust, or C++.
• Experience training large neural network models with 1B+ parameters, including pre-training, post-training, fine-tuning, or RL training.

Nice to have

• Previous work in post-training or RLHF.
• Experience training models used by millions of people.
• Strong interest in truth-seeking AI, useful models, reinforcement learning, and alignment methods.
• Ability to thrive in a meritocratic environment and take pride in delivering high-quality work.

Culture & Benefits

• Work on super-intelligence systems spanning compute, models, and applications.
• Equity as part of the total rewards package.
• Comprehensive medical, vision, and dental coverage.
• Access to a 401(k) retirement plan, short- and long-term disability insurance, life insurance, discounts, and other perks.