Developer Experience Engineer on the Codex team at OpenAI.

Creator of Instructor, a Python library for structured LLM outputs that OpenAI cited as inspiration for its structured outputs feature.

I write about building AI systems, open source, product work, taste, and personal growth at jxnl.co.

Angel investor and scout for Andreessen Horowitz. I've invested in companies including Lovable, Poke, Modal, Exa, Browserbase, Raindrop.ai, and Pydantic.

I ran a solo consulting practice helping startups transition to AI, and cohort-based training on RAG, AI agents, and independent consulting. Those offerings are now closed; the course content is available at Systematically Improving RAG.

Follow me on X or subscribe to my newsletter.