Simon-Willison

Simon Willison has a gift for naming things precisely. He coined “prompt injection.” He coined “AI slop.” Now, on Lenny’s Podcast, he’s naming a pattern that a lot of AI-augmented engineers are living but haven’t articulated: the lethal trifecta. The Lethal Trifecta Speed. Availability. Compulsion. Willison — Django co-creator, prolific blogger, and one of the most trusted practical voices in the AI developer space — describes a pattern he’s seen in himself and others: AI coding agents make you faster. Faster means you can do more. More availability means you can always be working. And the combination of capability and compulsion means you push past the limits that used to be enforced naturally by the slowness of unassisted work. ...

If you’ve used GitHub Copilot, Claude Code, Cursor, or OpenAI Codex and wondered what’s actually happening under the hood when the agent “thinks,” plans a multi-step fix, and edits three files at once — Simon Willison just published the definitive practitioner answer. Willison’s new chapter of Agentic Engineering Patterns — titled “How Coding Agents Work” — is the clearest technical breakdown yet of what separates a coding agent from a coding assistant, and why that distinction matters enormously for how you use and build with these tools. ...