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← Prometheans 100+ Simon Willison

LLM tooling pioneer, the most prolific AI blogger

Simon Willison

Developer & Writer — Independent

Profile

Simon Willison is the developer most other developers read when they want to know what LLMs actually do. A British engineer who co-created the Django web framework with Adrian Holovaty in 2003 at the Lawrence Journal-World newspaper, he spent a career building: Yahoo! Technology Development, early Fire Eagle geolocation, software architect at The Guardian, co-founding the conference directory Lanyrd with his wife Natalie Downe (Y Combinator, 2011; acquired by Eventbrite in 2013). He has been an independent open-source developer since 2020.

His two flagship projects are Datasette, a tool for exploring and publishing SQLite data as an interactive website, and LLM, a command-line utility and Python library for running prompts against every major model — OpenAI, Anthropic, Gemini, Mistral, local models via Ollama and llama.cpp — with a plugin architecture, SQLite logging, and, more recently, tool use. LLM is the cleanest way to put an API key in your shell and start actually using these models like a Unix citizen.

What makes him unavoidable is the blog. simonwillison.net was the most popular blog on Hacker News three years running, with 1,000+ posts a year — a mix of link commentary, deep technical write-ups, and meticulously annotated talks. He coined the term prompt injection in September 2022 and has been the clearest voice on LLM security ever since, later coining the lethal trifecta (private data + untrusted input + external communication) that describes why agentic systems keep getting owned. He has no vendor allegiance, runs every new model through his pelican-on-a-bicycle SVG benchmark, and explains what works in public. He also serves on the board of the Python Software Foundation.

For developers learning AI in 2026, Simon’s blog is probably the single highest-signal resource on the practical side of the field. He shows, not tells — every claim comes with a working example, a terminal transcript, or a one-liner you can run yourself.

Key Articles & Papers

Prompt injection attacks against GPT-3 2022 — The post that named the attack class. Still the cleanest explanation of why concatenating user input into a prompt is structurally unsafe, with parallels to SQL injection. Things we learned about LLMs in 2024 2024 — His end-of-year wrap-up. If you read only one piece to catch up on where LLMs actually are, read this — it covers the GPT-4 barrier falling, synthetic training data, multi-modality, and the economics of inference in one sitting. Here's how I use LLMs to help me write code 2025 — The most thorough personal account of AI-assisted programming available. Specific workflows, honest failure modes, tool choices — no hype. The lethal trifecta for AI agents 2025 — Access to private data + exposure to untrusted content + ability to exfiltrate externally = you are going to get owned. The most useful mental model for agent security so far. Pelicans on a bicycle 2024 — The homemade benchmark that went viral: ask each new model to generate an SVG of a pelican riding a bicycle. Absurd, but surprisingly revealing about spatial reasoning. Imitation Intelligence — PyCon US 2024 keynote 2024 — Full annotated talk arguing that LLMs are better understood as imitation engines than as intelligences. A good framing for developers new to the field. The last six months in LLMs, illustrated by pelicans on bicycles 2025 — Keynote from the AI Engineer World's Fair. A fast tour of the model landscape narrated by SVG birds. Large Language Models can run tools in your terminal with LLM 0.26 2025 — Announcing tool use in his LLM CLI. Demonstrates the tool-calling loop working across seven different model providers from one command-line interface.

Spotify Podcasts

An AI state of the union: We’ve passed the inflection point, dark factories are coming, and automation timelines | Simon Willison
An AI state of the union: We’ve passed the inflection point, dark factories are coming, and automation timelines | Simon Willison
AI tools for software engineers, but without the hype – with Simon Willison (co-creator of Django)
AI tools for software engineers, but without the hype – with Simon Willison (co-creator of Django)
How I Use Obsidian + Claude Code to Run My Life
How I Use Obsidian + Claude Code to Run My Life
Simon Willison: Using LLMs for Python Development
Simon Willison: Using LLMs for Python Development
[Ride Home] Simon Willison: Things we learned about LLMs in 2024
[Ride Home] Simon Willison: Things we learned about LLMs in 2024
471 - SIMON WILSON RETURNS! - Insane Afghanistan Exclusive, BANNED From USA, & How To Get Free Upgrades!
471 - SIMON WILSON RETURNS! - Insane Afghanistan Exclusive, BANNED From USA, & How To Get Free Upgrades!
114. Simon Wilson on Exploring NORTH KOREA, Being BANNED from the USA & Visiting 7 Continents In 7 Days
114. Simon Wilson on Exploring NORTH KOREA, Being BANNED from the USA & Visiting 7 Continents In 7 Days
143 - SIMON WILSON - How To Travel The World For Free!
143 - SIMON WILSON - How To Travel The World For Free!
Predictions 2026!!
Predictions 2026!!
Simon Says Part 2
Simon Says Part 2
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