3 coding problems. I solved them in Python. One about summing the cost of a shopping list using a dicionary. One about getting different lists of commands representing navigation in a terminal and writing code that determines whether you ended up in root or not (I used a stack). General questions and dicussions covering the modeling of a Data Science problem. E.g. we want to determine the price of cars, what would be relevant features, how would you clean the data, how would you avoid overfitting, feature selection, would you use dim reduction, etc.