The truth is that there is a lot of hype.

You need to be reasonably experienced and guide it.

First, you need to know that Claude will create nonsensical code. On a macro level it's not exactly smart it just has a lot of contextual static knowledge.

Debugging is not it's strongest skill. Most models don't do good at all. Opus is able to one-shot "troubleshooting" prompts occasionally, but it's a high probability that it veer of on a tangent if you just tell it to "fix things" based on errors or descriptions. You need to have an idea what you want fixed.

Another problem is that it can create very convincing looking - but stupid - code. If you can't guide it, that's almost guaranteed. It can create code that's totally backwards and overly complicated.

If it IS going on a wrong tangent, it's often hopeless to get it back on track. The conversation and context might be polluted. Restart and reframe the prompt and the problems at hand and try again.

I'm not totally sure about the language you are using, but syntax errors typically happens if it "forgets" to update some of the code, and very seldom just in a single file or edit.

I like to create a design.md and think a bit on my own, or maybe prompt to create it with a high level problem to get going, and make sure it's in the context (and mentioned in the prompts)