one round of online coding interview, there are three coding questions, which is around the difficulty of leetcode medium. It is pretty easy for those who already solved 200 leetcode questions. Second round of technical interview, lots of C++ technical problems, including memory leak with regards to pointer usage, virtual function, and static variable, and hash map, which I find it relatively difficult. Interviewee should be well prepared in this stage and be familiar with the technical details of these C++ details.