Drimva

Moonlake

Member of Technical Staff — Post-Training Infrastructure

San Francisco, CA · Staff · Full-time · Posted Oct 19, 2026

Experience
No specific number of years stated.

About the job

Leads reinforcement-learning infrastructure and model post-training to improve multimodal, vision-language, and code-generating agents.

What you'll do

  • Build RL and post-training pipelines, including systems for fine-tuning, preference optimization, reward modeling, and reinforcement learning.
  • Create trajectory-data, reward, verification, and evaluation systems for long-horizon agent tasks.
  • Scale distributed training and rollout generation, improving reliability, reproducibility, observability, and cost efficiency.

What they ask for

  • Real-world experience training large language, vision-language, multimodal, or code models.
  • Strong experience in reinforcement learning, post-training, or large-scale fine-tuning.
  • Experience building distributed training or high-throughput inference systems.
  • Strong Python skills and experience with PyTorch, JAX, or similar frameworks.

Nice to have

  • Experience at a frontier AI lab or organization operating large-scale training systems.
  • Experience with code-model post-training or autonomous coding agents.

Tools

Python, PyTorch, JAX

AI focus

Build training infrastructure and post-training methods for agents, including reinforcement learning, supervised fine-tuning, preference optimization, reward modeling, trajectory learning, and scalable evaluation; support agent, robotics, and embodied-model training.

Model-written summary · the original posting is authoritative

First seen Oct 29, 2026 · Last verified Nov 6, 2026 (UTC)