Amazon Software Development Engineer II interview questions

1st rounf f2f: 1. Given a snake ladder board , with the dice with favourable outcome. Find the minimum number of dice draws required to reach 100th position starting from 0. There are snakes and ladder in the game 2. Give K Sorted array , finally merge sort them. 3. Given a linked list with loop find the point where loop starts. 2nd round f2f: Design a time based validation check that can be applied to api, for example hitting google's map api more then 50 times in a minute will result in error, similarly design a system that checks in the no of calls that are happing in the sliding windows of given size. 3rd round design: Design a realtime ranking system , for example given a app like candy crush i would like to display user his current rank , globally, country wise etc