AI Research Engineer

This role involves researching and building AI agent systems for real-world applications, with a focus on post-training and reinforcement learning. You will work across research and engineering to take ideas into production, developing tooling and infrastructure to accelerate model development. The position is at a well-funded AI startup in San Francisco, offering a competitive salary and equity.

• Research and build AI agent systems for real-world applications
• Develop and improve RL environments for training and evaluation
• Work across research and engineering to take ideas into production
• Build tooling, infrastructure, and experiments to accelerate model development
• Collaborate with a small, high-calibre team solving challenging technical problems

• Strong software engineering fundamentals
• Experience using AI coding agents such as Cursor or Claude Code
• A notable AI agent research project and a separate implementation project
• Experience building or working with reinforcement learning environments
• Someone who enjoys contributing wherever needed, from research to product engineering and infrastructure

• Experience with post-training of foundation models