You speak of a senior developer, but your description and interview process seem to fit a mid level developer description. If he did not solve business/domain-specific problems or does not have a history of doing that for clients, it means that he is a mid level developer or a good junior developer with some experience.
Written by Oz Zeren
Writing for a better future. I work in Tech. I like Philosophy, History, Computers, Gaming, the Internet. I’m excited about the Creator Economy, Web 3.0, DAOs.