Member of Technical Staff — Post-Training Infrastructure
San Francisco, CAFull-timePosted 4d ago
About the role
Moonlake is building interactive world models and the infrastructure for intelligent systems to learn, evaluate, and interact within realistic virtual environments. This role leads reinforcement learning infrastructure and model post-training to improve large vision-language and code-generating agents.
Responsibilities
- Build RL and post-training pipelines for multimodal, vision-language, and code-generating agents
- Develop infrastructure for supervised fine-tuning, preference optimization, reward modeling, and reinforcement learning
- Create systems for collecting, filtering, replaying, and learning from agent trajectories
- Design rewards, verifiers, and evaluations for long-horizon agent tasks
- Improve agents’ ability to plan, write and execute code, use tools, recover from errors, and complete complex workflows
- Scale distributed training and high-throughput rollout generation across multi-GPU environments
- Improve training reliability, reproducibility, observability, and cost efficiency
- Help define Moonlake’s long-term strategy for agent, robotics, and embodied-model training
Qualifications
- 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
- Familiarity with supervised fine-tuning, preference optimization, reward modeling, and agentic RL
- Experience with code-generation agents, long-horizon evaluation, or tool-using systems
- Strong Python skills and experience with PyTorch, JAX, or similar frameworks
- Ability to work across data, models, environments, rewards, evaluation, and infrastructure
- Strong research judgment and a bias toward building reliable systems
Skills
Required:Reinforcement learningDistributed trainingFine-tuningPythonPyTorch or JAX
Benefits
- Not specified in the description
Last updated Oct 21, 2026. Interested? Apply on the company site.
About Moonlake
We’re building AI so anyone can create interactive worlds.
Moonlake AI is a team of Stanford CS PhDs, Math Olympiad and ACM ICPC medalists, industry veterans from NVIDIA, Meta, Epic Games, and Netflix, with the mission of democratizing studio-grade interactive worlds.
AIinteractive worldsdemocratizing creative technology
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