Amazon Software Engineer interview questions

They sent me a coding challenge. The first half was easy. It was about finding bugs in small programs. The second half required you to do multiple questions about logics and puzzles. I screwed that up. 40 questions in 40 minutes. The last one was a coding question. Easy in nature. But I had to find an optimized algorithm for it and it took quite a long time. They gave me 30 mins. The recruiter was kind, he extended the coding challenge for me twice, though 2 times I had problem logging in the system to do the coding challenge. So I had to contacted the system's support team and they resolved it very quickly within a day.