Research Scientist

About the role

Join a well-funded, stealth AI start-up building frontier reasoning models for scientific discovery. The team is tackling problems where models need to generate, evaluate and refine hypotheses across complex, multi-step scientific workflows. It's an opportunity to work on genuinely novel AI for Science research, combining frontier reasoning, post-training and reinforcement learning with a proprietary dataset that creates a significant competitive advantage. You'll work across the full research lifecycle, from designing training pipelines and reasoning datasets through to evaluation, experimentation and production systems. The emphasis is on building models that reason, not just models that respond.

Responsibilities

• Developing reasoning models and post-training pipelines for frontier language and multimodal models
• Building evaluation frameworks and benchmarks for complex, multi-step reasoning
• Improving model performance through reinforcement learning, alignment and scalable experimentation
• Exploring reasoning across multimodal inputs, where language and vision intersect to solve scientific problems
• Working closely with a small research team to rapidly test and deploy new ideas

Qualifications

• Strong experience in LLM post-training, RL for reasoning, reasoning datasets, evaluation or alignment is the priority
• Experience with multimodal or vision-language models (VLMs) is attractive, especially where you've worked on reasoning, although exceptional researchers from pure language model backgrounds are equally encouraged to apply
• Hands-on ownership of reasoning systems rather than simply working alongside them
• Could be an exceptional PhD graduate, Research Engineer, Applied Researcher or experienced Research Scientist

Pay

$250K - $400K Base (D.O.E.) + equity + very lucrative bonus/success structure

Location

San Francisco