Amazon Machine Learning Scientist, Alexa interview questions

The first part, the interviewers knew the area of machine learning extensively, and they asked me lots of theoretical question. The second part, they gave me an example of research plans and asked me how to approach this problem. The third part, the coding was simple; the numerical sorting question in Python. They connected the video chat from a medium size of a conference room, therefore the sound quality was not good. It was difficult for me to listen to the question even using headphone.