Bloomberg Software Development Engineer I interview questions

phone screen, one LC medium about backtracking and one medium using BFS/union find. Friendly interviewer and normal follow-ups. Superday Round 1. one non-leetcode problem, like a OOP, easy to medium. One LC medium. Getting rectangle sum from a mutable grid, I cannot remember how to use a fewick tree so I just use a prefix sum, the interviewer is alomst satisfied. Superday Round 2. One Leetcode Hard, find median in a data stream. Alot of followups on algorithm like why u choose this one not that one ... and a OOP. Interviewers are not friendly AT ALL with no hints.