1. I applied the SE position. 2. I received hackerrank test. 3. I completed the test with 100% answers correct and received onsite interview 4. The onsite interview asks several very easy programming questions and one math question, I got all correct but the last math question, the interviewer asks me to write the solution out without telling me the complexity constraints, the solution is correct, but I think they want a faster solution (that question needs the candidate knows some knowledge of number theory). They say the result is good and will give the assignment after several days. 5. One day later, I got rejected. Honestly, I dunno why. Thoughts: I think the interview process of this company is not professional, they should hire a software engineer who knows how to make better software and write better code instead of challenging the candidate with unrelated questions. I feel that there is one possibility they not aim to employ good software engineers but a bundle of cheap monkeys who does not have minds of software engineering but can just write cheap code fast.