I suspect the opposite is only true if you haven't taken the time to learn how to productively use LLMs for coding.

(I've written a fair bit about this: https://simonwillison.net/tags/ai-assisted-programming/ and https://simonwillison.net/2025/Mar/11/using-llms-for-code/ and 80+ examples of tools I've built mostly with LLMs on https://tools.simonwillison.net/colophon )

Maybe I've missed it, but what did you use to perform the actual code changes on the repo?

You mean for https://tools.simonwillison.net/colophon ?

I've used a whole bunch of techniques.

Most of the code in there is directly copied and pasted in from https://claude.ai or https://chatgpt.com - often using Claude Artifacts to try it out first.

Some changes are made in VS Code using GitHub Copilot

I've used Claude Code for a few of them https://docs.anthropic.com/en/docs/agents-and-tools/claude-c...

Some were my own https://llm.datasette.io tool - I can run a prompt through that and save the result straight to a file

The commit messages usually link to either a "share" transcript or my own Gist showing the prompts that I used to build the tool in question.