This caught my eye:

> The script ended up outputing code that uses variables outside of their scope, didn't utilize like 90% of the features of the language

Using variables outside of their scope sounds very unusual to me for Claude. You are using Claude Opus (4.5 or higher) and have set the thinking to High or above, right? Make sure you're not using Claude Haiku. Sonnet can be okay, but I'm sure the developers you've heard raving about it are all using Opus 4.8 or GPT 5.5, and all using it from within Claude Code or Codex (or OpenCode or Pi, tools like that anyway).

Claude should catch something like variables being outside of scope immediately when compiling, and fix it as soon as it notices the compiler bug.

> The script itself was also written in really weird way, utilizing recursion for pretty much everything when most of what it did could be done in simple loops...

That's actually a great opportunity to develop a new prompt to give to Claude. AI is really good at pattern matching. Take one of those weird recursion methods Claude came up with, then rewrite it as that simple loop that you would prefer, and show both to Claude. Then ask in the same turn: "This is how I prefer to write this code. Can you suggest a prompt to me that would encourage you to write this style of code instead in future?"

See if you can get Claude to reduce that down to a simple maxim or principal you can include in a startup prompt you provide at the start of each session, or into your global CLAUDE.md file that is loaded at the start of every Claude Code session. It might end up being a guideline like "Prefer simple loops over recursion whenever appropriate."

It's possible that the developers you've heard raving about AI have already developed startup prompts / CLAUDE.md files filled with similar maxims & principals, tailored specifically to how they like to code & work, evolved from months of working with AI.