Had a chat with the recruiter first.

During the chat, the recruiter asked all the general questions, like:

• What are you interested in?
• Why Affirm?
• Why do you want to leave your company? etc.

The phone screen tech question was a coding problem based on reservoir sampling.

It was not a difficult one. I was rejected two days later. I guess it was because I didn't complete the code, but if I had been given one more minute, I could have finished it.

The interviewer asked me to tell him my idea and then let me ask him any question, instead of letting me finish the code.