We have a take-home assignment as part of our interview process and they were able to get a working solution, but missed on design patterns that would make their code more maintainable and extensible, things that are usually learned from code-reviews by people who have had the experience of working with bad code.
This was more common in candidates who came to us from the tech departments of non-tech focused companies.
We lamented not being able to hire otherwise smart and personable candidates, but at the end of the day we only had headcount for 1 employee and we went with a different smart and personable candidate who had better early career opportunities.