Got a couple of phone calls from the engineering department. Questions on basic C++ programming questions (eg. write a quicksort function), data structure (eg. heap), some machine learning question (what is bias/variance trade-off, how does random forest work, what is regularization, etc.), and some optimization questions (how to prove that local minimum of a convex function is the global minimum.)
Interview questions [1]
Question 1
Something about binary heap, its time complexity, etc.