Senior Model Engineer

Quick Facts

• Role: Sr. Model Engineer (RL and post-training research)

Description

You will own ambiguous, hard research problems end-to-end for frontier coding agents, including forming hypotheses, designing experiments, building the training/evaluation/data needed to test them, and pushing results into the next model.

Responsibilities

• Design and run rigorous experiments to convert research ideas into measurable gains in model capability
• Improve data recipes via data quality, deduplication, and mixture experiments
• Define what makes RL data and rewards good, including grader design and preventing reward hacking
• Advance training science from architecture and scaling experiments to post-training recipes for coding and computer-use agents
• Build evaluations and targeted tasks that expose model weaknesses and guide where the team invests next
• Partner with engineers to take promising small-experiment results into frontier-scale training runs

Requirements

• 3+ years of hands-on experience training or post-training large neural networks (1B+ parameters), including pre-training, fine-tuning, or RL-based methods (e.g., RLHF, DPO)
• Experience writing production-quality code in Python with PyTorch, JAX, Rust, or C++
• Onsite role: must be able to work in person at the Palo Alto office

Benefits

• Equity
• Comprehensive medical, vision, and dental coverage
• Access to a 401(k) retirement plan
• Short- and long-term disability insurance
• Life insurance and various discounts/perks