Status: CS Student
Position: Software Engineering Intern
Location: London, UK
Date: January 18, 2020

Phone screen 1

Coding round with Bloomberg engineer. 1 question. Then asked how to find the shortest possible variant, and code it. There was no need to compile the code, just walk through with some test cases.

Phone screen 2

Coding design interview with 2 Bloomberg engineers. The round was divided in 2 parts. The first one was about designing a subway entry / exit registering system. Had to code it, explain the space/time complexity, explain the data structures used & talk about corner cases. The second part had a two city scheduling problem. They asked to code it and explain why the algorithm is correct. Finally, about 5 minutes was left for the questions for the interviewers. I asked what they liked about their job and why have they chosen Bloomberg as a company to work for.

Onsite: Coding round

Another 45 minutes round with two engineers. The interviewers asked questions about the resume, previous projects, why Bloomberg and other general behavioural stuff. There was only 1 question along the lines of LRU cache task. The idea was similar, using a Hash Map and a Linked List. They also asked to explain the space / time complexity of the solution.

Onsite: System design

An interview with a senior engineer. The interview consisted of one question, where I had to design a system that streams data from a stock exchange to different programs. The questions involved broad spectrum of knowledge - C++ memory management concepts, OS, networking and multithreading. I've came up with a decent, though not optimal approach and then we talked about possible improvements and constraints. The interview went in a very friendly atmosphere.

HR interview

This was an interview with a senior engineer and an HR. It consisted from a series of questions about my background, previous side-projects, interests and general walk-through the resume. They have also asked standard behavioural questions: why Bloomberg, what are you looking in your internship, what a good culture means for you and similar.

General advice

From the interview process, I clearly realized that the leetcode questions made only half of the process. The interviewers asked many questions related to specific concepts like C++, networking, OS. I had read few books on these topics, so I managed to answer about 70% of the questions. I also clearly stated the things I didn't know about. For them I tried to come up with an answer on the fly while explaining my reasoning to the interviewer.

My general advice would be to balance your interview preparation schedule by reading some articles / books / video on subjects you don't know about, at least you'll have a mild understanding and the interviewer will score it as 50%. Of course, you have to ace leetcode, no questions asked, but it is only a neccessary condition, not sufficient one (at least for my Bloomberg interviews).