Met with the Director of Engineering, followed by the Hiring manager for the typical get-to-know-you and your experience questions. Both people were very friendly and down to earth. Was given a take-home challenge (build backend APIs) that was supposed to be 4 hours. The problem is that it is only in c# and .NET, so if you're unfamiliar with those technologies (as I was), it will take longer than 4 hours. The challenge had some ambiguity which required you to interpret. I turned in the challenge with all endpoints working but then got a rejection a week and a half later with no explanation for why. I was not given a chance to explain my code, the tradeoffs I made, and how I interpreted the project's ambiguity.