Amazon Software Developer interview questions

I was trying to find a job out of college. Once I passed 3 phone interviews I was flown out to Seattle and spent a day interviewing at the headquarters. Most of the questions were not too hard, and I was able to arrive at what I thought was an acceptable answer for them all. The worst part was the lunch with the product manager. I was asked some software design questions over lunch which didn't go too well. I thought maybe that could be overcome and continued the process, but I was called a few days after I returned home letting me know that I would not be offered a position.

It was a phone interview back to back.. Questions were on hashtable. one question was print all permutations of a string. Other Question was on OOPS, Both inerviewers are really helpful