Amazon Non Software Development Engineer interview questions

Firstly there was an online test,and people shortlisted in that should go through 2 technical interviews provided 1st technical interview is cleared.I cleared the online test consisiting of aptitude,debugging and coding questions(two problems).And in my 1st technical inteview , Questions related to coding on topics like Graph applications,Linked list where asked.They test only your problem solving skills and your strength in Datastructures and Algorithms. I failed to clear the interview.