Amazon Applied Scientist interview questions

I applied online and was referred internally as well. I attended 2 phone interviews, the process of each lasts roughly 2 weeks from date confirmation to final decision. The first interviewer is from the team I'm applying to, and the questions are more machine learning oriented; the second interviewer is from CA office, and the questions are more speech recognition/processing oriented. I didn't do well in the second interview, which I think is the main reason I got rejected.