It was the usual phone screen backed up with an in-person. Most of the in-person went fine. Coverage of the app. New directions. My experience. Then they presented a remedial problem to be solved. (Happy Numbers) I solved it. But they didn't seem happy with the solution. I was struggling to see what relevance it had with the position at hand. (Backend API design). There were no questions on API design itself: traversals, security, versioning, etc.

Phone interview followed by a coding challenge. The recruiting team was very poor with their response time. My first call was completely blown off with no apology from the recruiter.