Senior Full-Stack Engineer Equity at a16z-backed AI behavior simulation startup

Job Title

Senior Full-Stack Engineer

$180k-$200k + Equity

a16z and MaC VC-backed AI startup simulating human behavior

San Francisco, USA

Join an elite 15-person team of exited founders and researchers building a platform that predicts human‑AI behavior. You will bridge the gap between complex multi‑agent simulations and intuitive product experiences, enabling teams to test features before shipping. This is a high‑velocity role for an engineer who thrives at the frontier of behavioral science.

• Work at the cutting edge of behavioral modeling alongside a world‑class team from Stanford, MIT, Airbnb, and Google.
• Backed by tier‑one investors including MaC VC, Protagonist, Weekend Fund, and scouts from a16z.
• High‑impact ownership where you ship bi‑weekly and see your code directly influence how global product teams make strategic decisions.

• Architect and scale the core Python platform used for designing complex behavioral experiments and multi‑agent simulations.
• Translate raw agentic system behaviors into actionable product insights through high‑performance React and Type Script frontends.
• Build critical system visibility and debugging tools that ensure simulation outputs are trustworthy and understandable for enterprise customers.

• Has 6+ years of experience building end‑to‑end production systems with deep proficiency in Python and modern frontend frameworks.
• Demonstrates a strong background in AI‑native development, specifically working with LLMs, agentic workflows, or complex simulation environments.
• Thrives in high‑intensity, low‑ego environments and values solving hard problems through in‑person collaboration in a San Francisco‑based HQ.