Bloomberg Software Engineer Interview Experience — Top K Frequent Elements Phone Screen

The first round was a standard phone technical screen — coding only, no behavioral questions. The difficulty is generally on the higher end of LeetCode medium, and the focus is on whether your data structure choice is reasonable and whether your code is clean. The question I got was to design a data structure that supports insert, delete, and returning the current Top K most frequent elements. The interviewer wasn't satisfied if you just used an off-the-shelf library — they wanted you to explain why you chose HashMap + Min Heap instead of sorting or a TreeMap. The time was around 45 minutes, but the coding itself took about 30 minutes, and the rest of the time went to follow-up questions about complexity optimization, edge case handling, and what you'd do if the data scale were in the hundreds of millions. Bloomberg's phone screen style is very direct, without much small talk, and the coding process felt fairly serious. I'd suggest getting used to coding in a shared document or online editor ahead of time, and keeping the rhythm of narrating your thought process while you write.