There were two rounds of phone interviews. It seems like there's an onsite after these two, but I didn't pass the second round.

The interviewers were very mechanical, and they asked a couple of questions related to probability and algorithms. The questions were standard but difficult, so preparation would be beneficial. Without prior exposure, solving them in time would be challenging. In my case, the interviewers did not offer hints.

Some scheme of independent coin tosses, but essentially asking the probability that Normal(10, 25) is negative. Also was asked to explain the concept of the Central Limit Theorem.

In an array of length n numbers, find an algorithm that finds the second largest number efficiently. There is an n + O(log n) answer.

Data structure with push() and randompop() features. Furthermore, a data structure with push() and weighted_randompop().