About the Role Join the founding engineering team at an early-stage AI company developing a foundational model from scratch with a novel architecture, rather than fine-tuning existing models. This hands-on role contributes to core model development as well as practical, production-ready LLM systems. What You'll Do • Build and improve foundational models across training, reinforcement learning, and model architecture. • Develop and ship production LLM applications, including agents, retrieval-augmented generation pipelines, or model-serving systems. • Create evaluations, benchmarks, and quality monitoring for LLM systems. • Contribute as a hands-on individual engineer across model development and application work. What We're Looking For • One to five years of professional engineering experience. • Practical experience building foundational models across the model-building pipeline, including training, reinforcement learning, and architecture. • A track record of building and shipping production LLM applications. • Strong Python skills and hands-on experience with an ML framework such as PyTorch. • Experience evaluating LLM systems through evaluations, benchmarks, or quality monitoring. • Interest in a ground-level individual contributor role. Compensation & Benefits Base salary range: $180,000 to $220,000 USD annually. Location On-site in San Francisco, California. Candidates should be based in the San Francisco Bay Area or willing to work on-site in San Francisco.