I'm using Opus on Claude Code and even on easy tasks, if you not review the changes properly, it creates tech debts. One of the most common issues is replicating the same logic with variables with different names (which makes grep harder to detect on future changes) in multiple places and lack of following project patterns. Even having a lot of .md files instructing to do the opposite. I still didn't find a workflow without human interaction that can be that efficient and reliable.