Amazon Software Engineer interview questions

2 basic OA and an onsite interview. The second OA is a disaster. First, the proctor asked me to remove everything on my table, and use a mirror to reflect the place behind the computer, which is very improper and troublesome. Furthermore, there is a typo in the API. Can you believe that? A typo in the API!! They spell "arbitrary" as "abritrary", thus I cannot access the field of the class they give me. Due to this silly mistake, my code couldn't even compile. But anyway, I pass the second OA and flight to Seattle for the onsite. I think I did very well in the final round. I completed all 3 milestones, including the 3rd which they said is optional. And I got 99% success rate. My friends got the offers while they only got 80%. And I don't think I did bad in other part of the interview. I feel very disappointed about this company.