Referred by a friend working at the company. Then a recruiter called to talk about the role and my background. Followed by a technical phone interview (1 hour).

The phone interview was not LeetCode-style, but a practical string processing hashmap problem. I used my own IDE and shared my screen via Zoom. The problem contained multiple steps, and the interviewer posted the next step when I finished each one. I completed all steps within the interview timeframe with all test cases passed. I also wrote a couple of test cases myself for thorough testing.

The interviewer didn’t hint me to optimize anything but let me ask him questions when there were approximately 10 minutes left. The next day, I received a rejection. I asked for feedback, but the recruiter said they could not provide any.

Overall, I'm pretty frustrated because the outcome was different from what I thought my performance was, and I was also unable to receive feedback.

Practical string and data structure problem.