Amazon Software Test Engineer interview questions

I was asked two questions in the phone interview. The interview was pretty easy. I did not get an offer because I needed visa sponsorship and could start work only in October

First interviewer called, about 10 minutes late. Seemed quite rude to me. When I asked what is this role, he said writing software that's all, nothing more. Asked me why I am interested in Amazon. I said great place to work... his counter was where did you hear that...etc... I was surprised 'coz I read before Amazon interview process is quite professional, I guess this was just an exception... Asked me difference between hash and binary tree...some questions from hashing, which one to use when. Asked me to code to find out whether two binary trees have the same structure (e.g. same right subtrees and same left sub trees by structure, not necessarily by value). I gave him a recursive answer, although I was not convinced, he seemed satisfied. Anyway. Asked me to send the code. He also asked me the challenging project I worked recently. When I gave some details (which I did during my Dell days) he said he won't be interested about the detail!!! In the second round, another guy called. Asked me some question from Resume and gave me a prime number code. I did write the code, he apparently scrutinizing every step. That was it. Did not get a call for the onsite.