3 rounds in total: 1nd. Face to face, coding. This one is easy and straight forward. You have to compile the code and pass all the test cases. 2nd. The interviewer cannot make the question clear. A stack design question. He imposed so many weird restrictions to the design, and he expects you know the answer. If you don't know the answer, you failed right away even though you figured it out at the end. 3rd. Didn't even get into the third round. Overall, it's a very unfriendly and unprofessional interview. They expect you know the answer. If you don't know it, you just fail. No chance for you.

Design a stack API.