Author here. The part about coding agents that wasn't clear to me was how much of the "magic" is in the underlying LLM and how much in the code around it making it into an agent.
When I realised that it's mostly in the LLM I found that a bit surprising. Also, since I'm not an AI Engineer, I was happy to realise that my "regular programming" skills would be enough if I wanted to build a coding agent.
It sounds like you were aware of that for a while now, but I and a lot of other people weren't. :)
That was my motivation for writing the article.