This was probably one of the most unprofessional interview experiences I have ever had the displeasure of participating in. I first applied for the position of Embedded Systems Engineer and was sent an online assessment (Hackerrank) a few months later. I passed this and was then called randomly out of the blue without prior warning. However, I was not able to answer the phone at the time and asked if the interviewer could call back. He said yes, but never did. I emailed the recruiters multiple times for follow-up but received no response. Then, a few weeks later, the recruiter finally called me again and told me that I passed the OA and could move onto the next step. Turns out, the next step was another OA for a different position (Software Developer) and was the same format as the first one. That's already 2 hours wasted doing these OAs. I passed this one again and was finally scheduled to do a final interview. This final interview was probably the worst final interview anyone could have. There were 3 interviews; only the first one could speak English. The next two could only speak Mandarin. You would think that an interview conducted for a job opening in Canada would be in English or French? Nope. This is very unprofessional and a huge waste of time. All in all, I wasted over 5+ hours in total from application to redundant OAs to 3 hours of virtual interviews being conducted in a very unprofessional manner. All this to receive a quick, "You were not selected." Please, save your time and DO NOT apply to the Vancouver position. It is a waste of time if you don't know Mandarin.

What is concurrency? Explain TCP/IP. Some really easy LeetCode question.