Simon Willison — Independent developer and writer documenting practical experiments, tools, and deep analysis around large language models, generative AI, web development, security, and emerging programming workflows through detailed posts and daily TILs.
145 articles from this blog
A speaker shares insights from a fireside chat on AI coding agents, discussing adoption stages, trust in AI output, and test-driven development with agents.
Anthropic's Claude Opus 4.6 and Sonnet 4.6 models now offer 1M context at standard pricing, contrasting with competitors' long-context premiums.
A developer builds custom, AI-assisted accounting software to handle complex multi-currency and tax needs, finding off-the-shelf solutions inadequate.
Shopify CEO uses AI coding agent to achieve 53% faster parse+render and 61% fewer allocations in the Liquid template engine.
Satirical article about a fictional 'Clean Room as a Service' that uses AI to circumvent open source licensing obligations.
An analysis of AI's impact on software development, based on interviews with 70+ developers, discussing automation, testing, and the future of coding.
AI-assisted coding reveals a long-standing divide between developers who prioritize craft and those focused on results.
Creating animated visualizations of sorting algorithms using AI tools, including Python's Timsort and a 'run all' comparison feature.
A quote from John Carmack on the pitfalls of over-architecting software for future needs, shared on a developer's blog.
Argues that AI coding agents should be used to improve code quality and reduce technical debt, not just speed up development.
New PostgreSQL 18 and SQLite features allow developers to copy database statistics to replicate production query plans in dev environments.
Explores how modern LLM coding agents adapt to new or private tools, challenging the 'Choose Boring Technology' assumption.
A quote from Joseph Weizenbaum on how simple AI programs can cause delusional thinking in people, shared on a tech blog.
OpenAI offers 6 months of ChatGPT Pro with Codex to core maintainers of significant open source projects, following a similar move by Anthropic.
Key questions for developers, managers, and stakeholders to audit a Rails codebase and identify technical debt and process issues.
Analysis of Anthropic's Pentagon contract and its branding as a 'moral' AI provider in a commodified AI market.
Explores the importance of manual testing by AI coding agents to complement automated tests, with practical patterns for Python, APIs, and web UIs.
A detailed analysis of a prompt injection attack against Cline's GitHub repo, leading to cache poisoning and a compromised NPM release.
OpenAI announces GPT-5.4 and GPT-5.4-Pro models with enhanced coding, document creation, and a 1M token context window.
Explores the legal and ethical implications of AI coding agents creating "clean room" rewrites to relicense open-source software, using the chardet Python library case.
