Microsoft Software Engineer Senior interview questions

You will have 4 rounds of interviews; each will be 45 minutes in length with short 15 minutes breaks in between. Each interview will be comprised of technical and behavioral questions

A one hour interview with an engineer. He had an ill defined problem about a binary tree, and got frustrated when asked for more details about the problem. The solution was a simple recursive function, but he wanted you to walk through what it was doing and why. No feedback, just a generic reject email.