Amazon Software Developer Engineer II interview questions

Did two phone interviews. The first was a pre-screening programming test in which they asked me to take a function that traverse through a list and point out all the flaws. Most of the flaws were related to lookup inefficiency, big O notation stuff. The second phone interview asked me to write a function that contacts an Amazon server and asks for the competitors prices and returns a list with the competitor prices and names. From there I had to find the the competitor with the lowest price efficiently. Also, afterwards they ask about big O notation and how data structures work behind the scenes.

Amazon uses a basic aptitude test consisting of 20 questions for the intitial screening. The aptitude also contains two coding questions which can be done in either C,C++,Java. It then contains 3 rounds of interview - 2 technical and 1 HR round.The interview questions are mainly concentrated on data structures,algorithms and bit of operating systems.