To be clear, this was not a vibe coding exercise, despite the title. The author supervised and reviewed the code changes at every step, caught mistakes and sub-optimal solutions, and worked with the LLM to fix and improve those problems.
This is not someone who just said "build me X", left it to run for a while, and then accepted whatever it wrote without reading it.
(I'm not criticizing the article's author here. It was an excellent, thoughtful read, and I think an article that was actually about something vibe-coded would be boring and not really teach me anything useful.)