Microsoft Interview questions SDE 2

Got the offer from microsoft Here is list of Questions asked : Round 1 : Coding round Two Coding Questions related to HashMap Round 2 : Technical interview Asked question Trapping Rain Water Another question asked Kth Largest Element in an Array - I have solved this problem using heap, then he asked me if I can optimize it, so I gave QuickSort Algorithm for that Round 3 : What Is Denial-Of-Serivce attack and how to resolve this issue, I told using Rate Limiter, so he asked me various algorithm which is used to implement Rate Limiter. Question related to how can I find the Time Complexity and Space complexity of the program without looking into the code, and just by executing the code we need to detect time and space complextiy. Round 4 : System design question related to design the hotel booking system , which will find the hotel within range of 1 km and then question is narrowed down to heap sort and write algo to find Nth smallest integer Round 5 : It was managerial round, System design question asked related to design BookMyShow kind of app, and what rest APIs will I create for BookMyShow app