Celonis Senior Software Engineer C++ interview questions

It was a horrible interview. The interviewers made me understand from the start that they didn't want to hire me. The microphone of one of the two interviewers broke and resonated, when he spoke to me, the other interviewer and I barely heard anything. Finally, the woman interviewing had to explain what he was asking me. Interview process: First, I had a chat with HR and then a coffee talk with a lady, then they gave me an assignment for the next few days, but they said: no spend more than 3 hours on this task. I followed their instructions, didn't spend more than 3 hours on the task. When I finished 3 hours, I developed the problem, made it more complex and improve my first solution, and also do benchmarks to show them why STL C++ is slower than third party v ... v ... However, they didn't even give me a chance to show off my presentation. That means all the time and effort the candidate puts into making the presentation is wasted. We completed the interview process in just 60 minutes even with a reservation time of 90 minutes. After a few days they gave me an appointment (10 minutes) to hear where I went wrong, but this also disappointed me. HR didn't show me a score table but just said a few sentences, and that's it. They seem to really want to imitate the recruiting style of the top companies: MAANG (formerly FAANG), but their imitation is only half-hearted, and nothing is really good.