After a former boss referred/submitted my resume via the Amazon employee referral program, I was contacted via e-mail to schedule a telephone interview and was advised a math flow question would be part of the interview. About a week later, the recruiter called, introduced herself, and explained a bit about Amazon and the position to which I had applied. Following the brief background information, she began her question starting with 2 math flow problems. She even gave me a hint to help out. The questions were something like, "If you have x number of employees, working y hours, packing boxes at a rate of z boxes per hour, how many boxes can they pack in a week? After successfully navigating the math flow questions, she began asking behavioral questions ... "Why Amazon?" "Have you ever used metrics?" "Can you give me an example of a time you improved a process? Can you give me some metrics to back it up?" "Give me an example of a time you had to resolve a problem with someone who worked for you" ... etc.
The questions were very straightforward and the interview went well. After she was done asking questions, she gave me a chance to ask questions and I did. My final question was, "Do you have any concerns regarding my qualifications for this position?" She told me she thought I was a great candidate and wanted to know if I was available for an onsite interview in Kentucky. I told her I was. Later, she e-mailed me some prep materials and the Amazon travel coordinator arranged my airfare, lodging, and rental car. I was told I would be interviewed by four different people, to include an HR rep, and one who would give me more math.
The day of the onsite interview, there were three other candidates. Two of them were applying for the same position at the same location to which I had applied. The other was applying for a different position at a different location. We started with a tour of the facility and were encouraged to ask questions. When the tour was over, we were taken to a small conference room and asked to fill out some paperwork. They wanted to know our geographic preferences, previous salary, etc. We were then given calculators and had 15-20 minutes to fill out a math flow sheet. This sheet was used later during the math portion of our interview.
After completing the math worksheet, the interviewers came to the conference room and escorted us individually to their respective areas for our interviews. I interviewed with the HR rep first, then the general manager, then the math guy/senior operations manager, then another senior operations manager. I was escorted back to the conference room after each interview and waited for my next interviewer to get me. Each interview took about 45 minutes. There were no strange questions. All the interviewers were very down to earth and personable. Other than the math, there were no curve balls, and one could argue that the math was straightforward as well. During the math interview, I was asked to walk up to the whiteboard and explain how I arrived at my answers on the worksheet. The interviewer wanted to see how I think. After I finished, he changed the parameters of the original problem and wanted me to solve it and explain my thinking as I want along. After completing the second iteration, he change the parameters again and asked me solve and explain as before. I eventually arrived at the correct solution, although I made a couple very basic errors along the way. I think my interviewer even got mad at me! Regardless, I finished that portion and then went for the final interview.
There was a 10-15 minute break after the second or third interview. After completing all the interviews, the recruiter, who was our "hostess/chaperon" throughout the process, gave us the timeline and answered any additional questions we had. She said we would hear from them sometime the following week (my onsite interview was on a Thursday), one way or the other. The next week, I received an e-mail indicating Amazon would not be moving me forward in the interview process. I was given no reason for the decision (which I've heard is the industry standard.)