Today's high-end LLMs can do a lot of unsupervised work. Debug iterations are at least junior level. Audio and visual output verification is still very week (i.e. to verify web page layout and component reactivity). Once the visual model is good enough to look at the screen pixels and understand, it will instantly replace junior devs. Currently if you have only text output all new LLMs can iterate flawlessly and solve problems on it. New backend dev from scratch is completely doable with vibe coding now, with some exceptions around race conditions and legacy code comprehension.