My favorite hiring process I've been a part of was with a AI startup. The initial phase was a list of maybe a dozen questions in an email. Fairly open-ended questions about how I perceived aspects of intelligence, ontology, and general philosophical concepts. Then a day at the company talking with the founder and the team, walking through their concept, long two way discussions about it, and a discussion about the direction of AI in general. Didn't get into a lot of coding details, it was assumed if I could participate in the conversation at a sufficient level that I'd be able to work the rest of it out. Which was true. Great process, completely appropriate for that situation.