Promptfoo, Inc.

Promptfoo builds open-source AI security testing tools used by 127 of the Fortune 500 to find and fix vulnerabilities in LLM applications. Founded by Ian Webster (former Discord LLM engineering lead) and Michael D'Angelo (former VP Engineering & Head of AI at Smile Identity), the company brings deep practitioner experience scaling AI to hundreds of millions of users. Backed by Andreessen Horowitz and Insight Partners, Promptfoo operates the world's largest AI security community with over 300,000 developers. The platform covers red teaming, guardrails, model security, and evaluations — all integrated into developer workflows.