The interview was very laid back and the interviewers were super nice. They would ask questions and give you hints to find the answer if needed. The first round was a coding assignment in C++ which was sent to me an hour after I applied for the job. The test was similar to what others have described: telling what a function does, finding bugs, code optimisation, use cases, etc. Then, a phone interview was scheduled for discussing my answers. At the final stage, I had a 3 hours interview in Belfast office. I was asked basic questions about Python, Numpy, Git, Linux, and Machine Learning followed by some behavioural questions. Finally, we had a lunch together. I really enjoyed the friendly manner of the interviewers and the prompt responses after each interview stage (less than a week). I asked for feedback after getting rejected for the position and received some helpful feedback from them.

I applied online. I received immediately an online test. The process took 3 days because I could't take it that day. A set of questions was about a piece of code (meaning, performance, refactoring). The another set was about a voice mail system, with use cases, actors, variations, exceptions. The overall idea is to know very well the idea of performance and how to implement it in code and have a very good understanding of program design.