All I have to say is not WASTE your time on the Canonical interview. 24 hours after applying, I received an email stating I passed the resume screening round, and the hiring manager asked me to do a screening task with 30 questions about my experience, and my high school and university life. At that moment, I valued the interview, and I wrote at least 400 words for each question and spent two weeks (Christmas break) on this. After the new year, I received a psychological test and wasted one day preparing it, I answered all the questions in a fast and accurate way. One day later, I got a rejection email from the hiring manager, who said he would not progress my application. Instead of giving me a proper reason for rejection, the hiring manager stated that Canonical is a great company and everyone wants to work here, and that's why Canonical received 80,000 applications each year(to be honest, I don't understand what the logic behind this, showing off? maybe). So I wrote an email to follow up on the reason and never heard again from him.

It's an extremely long process that includes standardized tests, take home assignments, and several rounds of interviews. It was at least 5 rounds long and you interview across different teams.