Amazon came to my college and was hiring. They interviewed a lot of people, basically two 1:1 interviews 45 minutes each. I felt it wasn't organised because there wasn't enough time left to ask questions. The first guy asks me about sorting and asks he to describe efficient algorithms. I tell him about Quicksort and Mergesort. But then he mentioned there's only a few possible numbers; and asked me to sort in linear time. I hinted towards radix sort, but he wanted something else. Finally he gave me an hint towards counting sort, which I then coded. There were some other questions, which I forgot about. The second guy asked me about how Hashtables work, chaining, collision and all that. Then he proceeded to trees, and asked about traversals, both recursive and non recursive. Overall it was ok, I got the offer 2 weeks later. The HR is really unorganised.