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Simon Willison

Articles about AI Agents, software-development, coding-agents.
104 articles · Last updated: 16/03/2026

Articles

Use subagents and custom agents in Codex

how-to · 16/03/2026 · ai-agents, custom-agents, openai-codex

Coding agents for data analysis

tutorial · 16/03/2026 · data-analysis, coding-agents, workshop

A quote from A member of Anthropic’s alignment-science team

explanation · 16/03/2026 · ai-ethics, alignment-science, generative-ai

Introducing Mistral Small 4

explanation · 16/03/2026 · ai-models, machine-learning, coding-languages

How coding agents work - Agentic Engineering Patterns

explanation · 16/03/2026 · coding-agents, large-language-models, token-processing

A quote from Guilherme Rambo

explanation · 16/03/2026 · macbook, security, hardware-indicators

What is agentic engineering? - Agentic Engineering Patterns

explanation · 15/03/2026 · agentic-engineering, coding-agents, llms

My fireside chat about agentic engineering at the Pragmatic Summit

explanation · 14/03/2026 · ai-adoption, agentic-engineering, test-driven-development

A quote from Jannis Leidel

explanation · 14/03/2026 · ai-ethics, open-source, github

Shopify/liquid: Performance: 53% faster parse+render, 61% fewer allocations

explanation · 13/03/2026 · performance-optimization, coding-agents, liquid-template-engine

1M context is now generally available for Opus 4.6 and Sonnet 4.6

explanation · 13/03/2026 · opus-4-6, sonnet-4-6, openai

A quote from Craig Mod

explanation · 13/03/2026 · accounting-software, custom-development, productivity-tools

MALUS—Clean Room as a Service

explanation · 12/03/2026 · satire, open-source, ai-robots

A quote from Les Orchard

explanation · 12/03/2026 · ai-coding, developer-divide, software-development

Coding After Coders: The End of Computer Programming as We Know It

explanation · 12/03/2026 · ai-assisted-development, future-of-programming, software-engineering

A quote from John Carmack

reference · 11/03/2026 · software-engineering, john-carmack, yagni

Sorting algorithms

explanation · 11/03/2026 · sorting-algorithms, python, animation

AI should help us produce better code - Agentic Engineering Patterns

how-to · 10/03/2026 · ai-agents, technical-debt, software-development

Production query plans without production data

explanation · 09/03/2026 · postgresql, query-planning, database-statistics

Perhaps not Boring Technology after all

explanation · 09/03/2026 · llms, programming, technology-choices

A quote from Joseph Weizenbaum

reference · 08/03/2026 · computer-history, ai-ethics, internet-archive

Codex for Open Source

explanation · 07/03/2026 · open-source, ai-tools, chatgpt

Clinejection — Compromising Cline’s Production Releases just by Prompting an Issue Triager

explanation · 06/03/2026 · prompt-injection, github-security, ai-triage

A quote from Ally Piechowski

how-to · 06/03/2026 · rails, code-audit, software-development

Agentic manual testing - Agentic Engineering Patterns

how-to · 06/03/2026 · manual-testing, coding-agents, automated-tests

Anthropic and the Pentagon

explanation · 06/03/2026 · ai-ethics, military-ai, ai-competition

Can coding agents relicense open source through a “clean room” implementation of code?

explanation · 05/03/2026 · open-source, clean-room-implementation, coding-agents

Introducing GPT‑5.4

explanation · 05/03/2026 · gpt-5-4, api-models, openai

Anti-patterns: things to avoid - Agentic Engineering Patterns

how-to · 04/03/2026 · agentic-engineering, code-review, pull-requests

Something is afoot in the land of Qwen

explanation · 04/03/2026 · ai-models, team-resignation, alibaba

Gemini 3.1 Flash-Lite

explanation · 03/03/2026 · ai-models, cost-efficiency, product-update

A quote from Donald Knuth

explanation · 03/03/2026 · generative-ai, automatic-deduction, creative-problem-solving

February sponsors-only newsletter

explanation · 02/03/2026 · openclaw, agentic-engineering, strongdm

GIF optimization tool using WebAssembly and Gifsicle - Agentic Engineering Patterns

how-to · 02/03/2026 · gif-optimization, webassembly, gifsicle

A quote from claude.com/import-memory

how-to · 01/03/2026 · data-export, personalization, ai-assistants

Interactive explanations - Agentic Engineering Patterns - Simon Willison's Weblog

explanation · 28/02/2026 · cognitive-debt, interactive-explanations, ai-agents

Unicode Explorer using binary search over fetch() HTTP range requests

how-to · 27/02/2026 · http-range-requests, unicode, binary-search

Please, please, please stop using passkeys for encrypting user data

explanation · 27/02/2026 · data-encryption, user-security, authentication

Free Claude Max for (large project) open source maintainers

reference · 27/02/2026 · open-source, maintainers, claude-max

An AI agent coding skeptic tries AI agent coding, in excessive detail

explanation · 27/02/2026 · ai-agents, machine-learning, rust-programming

Hoard things you know how to do - Agentic Engineering Patterns - Simon Willison's Weblog

how-to · 26/02/2026 · coding-agents, software-development, knowledge-management

A quote from Benedict Evans

explanation · 26/02/2026 · ai-engagement, openai-strategy, user-experience

Google API Keys Weren’t Secrets. But then Gemini Changed the Rules.

explanation · 26/02/2026 · api-keys, google-maps, gemini

A quote from Andrej Karpathy

explanation · 26/02/2026 · ai-programming, coding-agents, ai-impact

I vibe coded my dream macOS presentation app

how-to · 25/02/2026 · macos-development, presentation-tools, swiftui

Claude Code Remote Control

explanation · 25/02/2026 · remote-control, claude-code, software-updates

Linear walkthroughs - Agentic Engineering Patterns - Simon Willison's Weblog

how-to · 25/02/2026 · coding-agents, showboat, swiftui

A quote from Kellan Elliott-McCrea

explanation · 25/02/2026 · technology, emotional-intelligence, web-development

tldraw issue: Move tests to closed source repo

explanation · 25/02/2026 · open-source, intellectual-property, software-development

First run the tests - Agentic Engineering Patterns - Simon Willison's Weblog

how-to · 24/02/2026 · automated-testing, ai-agents, software-engineering

go-size-analyzer

explanation · 24/02/2026 · go-tooling, binary-analysis, webassembly

Writing code is cheap now - Agentic Engineering Patterns - Simon Willison's Weblog

explanation · 23/02/2026 · agentic-engineering, software-development, code-quality

Red/green TDD - Agentic Engineering Patterns - Simon Willison's Weblog

explanation · 23/02/2026 · test-driven-development, coding-agents, software-engineering

Ladybird adopts Rust, with help from AI

explanation · 23/02/2026 · rust, ai-assisted-coding, software-engineering

Writing about Agentic Engineering Patterns

explanation · 23/02/2026 · agentic-engineering, coding-agents, software-development

Reply guy

explanation · 23/02/2026 · ai-bots, twitter-engagement, generative-ai

A quote from Paul Ford

explanation · 23/02/2026 · vibe-coding, communication, empathy

A quote from Summer Yue

explanation · 23/02/2026 · ai-tools, inbox-management, automation

London Stock Exchange: Raspberry Pi Holdings plc

explanation · 22/02/2026 · stock-market, ai-projects, raspberry-pi

The Claude C Compiler: What It Reveals About the Future of Software

explanation · 22/02/2026 · ai-coding, software-development, compiler-design

How I think about Codex

explanation · 22/02/2026 · openai, codex, ai-agents

Andrej Karpathy talks about “Claws”

explanation · 21/02/2026 · ai-agents, claws, openclaw

Quoting Thibault Sottiaux

explanation · 21/02/2026 · thought-leadership, interviews, technology

Quoting Thariq Shihipar

explanation · 20/02/2026 · Agent-Native Architecture, Prompt Engineering, Claude Code

Taalas serves Llama 3.1 8B at 17,000 tokens/second

explanation · 20/02/2026 · AI Agents, Model Optimization, Hardware Startups

ggml.ai joins Hugging Face to ensure the long-term progress of Local AI

explanation · 20/02/2026 · OpenAI API, AI Agents, Anthropic API

Adding TILs, releases, museums, tools and research to my blog

explanation · 20/02/2026 · Open Source Projects, Web Development, AI Agents

Recovering lost code

how-to · 19/02/2026 · Prompt Engineering, Agent-Native Architecture, Claude Code

Gemini 3.1 Pro

reference · 19/02/2026 · Prompt Engineering, AI Agents, LangChain

LadybirdBrowser/ladybird: Abandon Swift adoption

explanation · 19/02/2026 · Software Development, Programming Languages, Project Management

SWE-bench February 2026 leaderboard update

reference · 19/02/2026 · OpenAI API, Prompt Engineering, AI Agents

Experimenting with sponsorship for my blog and newsletter

explanation · 19/02/2026 · Blogging, Sponsorship, Independent Publishing

The A.I. Disruption We’ve Been Waiting for Has Arrived

explanation · 18/02/2026 · ai-disruption, coding-tools, technology-impact

A quote from Martin Fowler

explanation · 18/02/2026 · llms, software-development, expert-generalists

Typing without having to type

explanation · 18/02/2026 · Programming Productivity, Type Hints, AI Agents

Rodney v0.4.0

reference · 17/02/2026 · browser-automation, cli-tools, software-release

Introducing Claude Sonnet 4.6

explanation · 17/02/2026 · ai-models, anthropic, sonnet-4-6

Supervisor, not overseer

explanation · 12/02/2026 · Ethical Considerations in AI, AI Agents, Language and Terminology

Covering electricity price increases from our data centers

explanation · 12/02/2026 · Energy Consumption, Corporate Responsibility, AI Agents

Introducing GPT‑5.3‑Codex‑Spark

explanation · 12/02/2026 · OpenAI API, Prompt Engineering, AI Agents

Gemini 3 Deep Think

explanation · 12/02/2026 · Creative AI, Prompt Engineering, AI Agents

Quoting Anthropic

explanation · 12/02/2026 · Anthropic API, Claude Code

An AI Agent Published a Hit Piece on Me

explanation · 12/02/2026 · AI Agents, Open Source, GitHub

cysqlite - a new sqlite driver

explanation · 11/02/2026 · Python Programming, WebAssembly, Cython

Skills in OpenAI API

how-to · 11/02/2026 · OpenAI API, Prompt Engineering, Claude Code

Quoting Andrew Deck for Niemen Lab

explanation · 11/02/2026 · Large Language Models, Prompt Engineering, AI Agents

GLM-5: From Vibe Coding to Agentic Engineering

explanation · 11/02/2026 · Agent-Native Architecture, Prompt Engineering, AI Agents

Introducing Showboat and Rodney, so agents can demo what they’ve built

explanation · 10/02/2026 · Agent-Native Architecture, AI Agents, Software Testing

AI Doesn’t Reduce Work—It Intensifies It

explanation · 09/02/2026 · Cognitive Load, AI Agents, Sustainable Working Practices

Structured Context Engineering for File-Native Agentic Systems

explanation · 09/02/2026 · Agent-Native Architecture, AI Agents, Prompt Engineering

Quoting Thomas Ptacek

explanation · 08/02/2026 · Anthropic API, AI Agents, Vulnerability Research

Kākāpō mug by Karen James

explanation · 08/02/2026 · Personal Appreciation, Kākāpō Conservation, Ceramic Art

Vouch

explanation · 07/02/2026 · AI Agents, GitHub, Open Source Contributions

Introducing Deno Sandbox

how-to · 03/02/2026 · Python, Deno, Security

Quoting Brandon Sanderson

explanation · 03/02/2026 · Generative AI, Artistic Expression, AI Ethics

January sponsors-only newsletter is out

explanation · 03/02/2026 · AI Agents, Prompt Engineering, Agent-Native Architecture

A Social Network for A.I. Bots Only. No Humans Allowed.

explanation · 02/02/2026 · AI Agents, Journalism, Generative AI

Introducing the Codex app

explanation · 02/02/2026 · AI Agents, Agent-Native Architecture, OpenAI API

TIL: Running OpenClaw in Docker

how-to · 01/02/2026 · AI Agents, Docker, OpenClaw

Singing the gospel of collective efficacy

explanation · 31/01/2026 · Collective Efficacy, Social Impact, Community Engagement

Quoting Andrej Karpathy

explanation · 31/01/2026 · Generative AI, AI, OpenAI

We gotta talk about AI as a programming tool for the arts

explanation · 30/01/2026 · Generative AI, AI-Assisted Programming, AI Ethics

Quoting Steve Yegge

explanation · 30/01/2026 · AI Agents, Agent-Native Architecture, Prompt Engineering

Moltbook is the most interesting place on the internet right now

explanation · 30/01/2026 · AI Agents, Prompt Engineering, OpenAI API