I used a web project in the demo because I figured it would be familiar to a wide range of developers, but actually many nontrivial pieces of Plandex have been built with the help of Plandex itself.

That's not to say it's perfect or will never make "noob-level" mistakes. That can definitely happen and is ultimately a function of the underlying model's intelligence. But I can at least assure you that it's quite capable of going far beyond a trivial web project.

It's also on me to show more indepth examples, so thanks for calling it out. I'd love it if you would try some of the projects you mention and let me know how it goes.