Adobe Data Mining/Machine Learning Engineer Position interview questions

Two people conducted one hour phone interview. They called separately so each had half hour. One of them is the hiring manager, he explained that the team is mainly about data mining. Then asked my real world experience with data mining, and eventually that lead to amazon recommendation system. So he asked me how I would design the recommendation system? He was polite and the conversation was pleasant. The second person is a senior engineer in the team. He asked my experience and skills required for the position. There was a problem in our discussion, quite often, I had hard time understand what he wanted to ask. He was trying to refine his question several times, in the end, we both worked very hard to define the problem. Overall, he is a nice person. I told the manager that I wouldn't be available soon, that, maybe plus others leads to no forward.