Full Stack Software Engineer - RL environments

🚀 Software Engineer — RL Environments | San Francisco

We’re hiring a Software Engineer focused on RL Environments to join a fast-growing applied AI research company working directly with leading frontier model labs.

You’ll help design the environments, reward signals, evaluations, and data that influence how advanced models are trained and improved.

🧠 What you’ll do

• Build RL environments, simulations, and task frameworks
• Develop reward signals and evaluation systems for RLHF / RLVR
• Analyse model and agent failure modes
• Run post-training experiments
• Build synthetic and real-world data pipelines
• Work closely with researchers to turn training objectives into production systems

⚙️ What we’re looking for

• Strong reinforcement learning experience
• Experience building environments, rewards, or model evaluations
• Strong Python engineering skills
• Ability to build and deploy production systems
• Experience with Docker, Kubernetes, or similar infrastructure
• Fast-moving, high-ownership mindset

⭐ Strong pluses

• Experience at an RL environment, AI evaluation, benchmarking, or AI safety organisation
• High-growth startup, early engineer, or founder experience
• Exceptional technical achievement or standout internships

📍 San Francisco — on-site

🎓 Primarily targeting candidates with 1–5 years of experience, although exceptional new graduates may be considered.