Michael D'Angelo
I'm a Member of the Technical Staff at OpenAI, working on Promptfoo and Codex Security. I help secure AI systems and use AI to find software vulnerabilities. I co-founded Promptfoo before it joined OpenAI in 2026.
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McKinsey's Lilli Looks More Like an API Security Failure Than a Model Jailbreak
Why the reported Lilli incident looks like an application-security chain reaching an AI system, not a model jailbreak.
(opens in a new tab)Promptfoo is joining OpenAI
Announcing that Promptfoo has agreed to be acquired by OpenAI.
(opens in a new tab)Notes on the Claude Code 2.1.0 outage
A changelog formatting change took down Claude Code. Lessons about parsing human docs as machine data.