Amazon Software Engineer interview questions

I post resume on Monster.com. Few days later, received a call from Amazon asked if I was interested in carrer opportunities with Amazon.com. I said yes, then they arranged a phone-screen three days later. During the phone-screen, the person asked some technical questions, something like: You are given two lists of strings, print out all the alphabet appear in the lists in order and how many times. Given a 2D 100*100 image, how will you shrink it to 50*50 image? Since you are working on web application, what would be the problem you think Amazon would encouter ? before asking technical question, he asked why Amazon and why left current position. After several technical questions, he started to talk about my resume. Describe the current job, specifically asked how did I do performance tuning (I listed an example on resume that one data loading module was 7 times faster than before being tuned). Finally, of course, he asked if i had any questions.