The process was long, but generally pleasant.

A recruiter contacted me, and we had a short call to discuss the position, my availability, and experience. We scheduled an interview for three weeks later.

On the day of the interview, I waited for the interviewer for 40 minutes and e-mailed one of the coordinators to check what was wrong. They sent me an explanation that the interviewer could not attend, but I had already been waiting for the duration of what was supposed to be the interview. We rescheduled, and the interview was held the next week.

There was another mix-up, since they had not sent me an invitation for the online meeting. The interviewer was very nice and helpful, although I don't feel like I did too well. We had a brief introduction chat. He posed the questions, explained the terms he used, gave me good tips, and answered my questions at the end.

I received feedback two and a half weeks later, after asking.

Write an algorithm that checks if a binary tree is balanced. Improve it and determine its complexity.