Founding Engineer, Full Stack

About the Company We're representing a YC-backed, early-stage AI startup building a new category of tooling: helping brands understand and shape how AI models perceive them. The product applies interpretability techniques to influence what large language models "think" about a brand, and it's already driving strong, fast-growing revenue with major enterprise customers. You'd be one of the first engineers on a very small, high-caliber founding team. Founded 2024 · ~5 people · Industry: AI, Marketing The Role As a founding engineer, you'll own product end-to-end across the full stack and help set the technical foundation as the company scales. This is a hands-on, high-ownership seat where research, infrastructure, and shipped product all sit with you. What you'll be doing Building and extending a context-management platform that powers agentic workflows across customer data, communications, and deliverables Using black-box interpretability techniques to understand how LLMs form opinions about brands and competitors Owning features end-to-end, from customer need through research, infrastructure, and shipped product Helping establish engineering patterns and practices around agentic coding tools Building internal automation and custom software for clients using AI agents Tech stack: Python, React, Terraform, AWS, LLMs, Claude Code Requirements 2-5 years of full-stack engineering experience, with hands-on Python and React Prior experience at a high-growth startup (seed / Series A stage or later) Demonstrated experience building agentic or LLM-based systems A bachelor's degree in any field (does not need to be computer science) Strong communication skills - able to explain technical work clearly to non-technical stakeholders and collaborate on a small team Based in or willing to relocate to San Francisco for full-time on-site work Nice to Haves Deep technical work in ML/AI, interpretability, or research-adjacent engineering Published research or scientific research experience Early adopter of agentic coding tools such as Claude Code or Cursor Why Join Founding-engineer ownership at a tiny, high-performing team defining a brand-new AI category Real revenue traction and enterprise customers already in production Direct work with an experienced, technical founding team Competitive base plus meaningful early equity Details Location: San Francisco, CA Work policy: On-site, 5 days/week Compensation: $170K - $250K + equity Visa sponsorship: No new sponsorship; open to visa transfers (e.g. OPT, H-1B), with support for existing visa holders Employment type: Full-time