I'm the OP and this is the exact point of the post. Whoever handed you that project did not have Claude code running it end to end in a production-like environment.
Whether you like the vibe coded app or not, you would have had fewer errors if Claude had been testing it end to end while vibe coding.
Whether you like the vibe coded app or not, you would have had fewer errors if Claude had been testing it end to end while vibe coding.