I just went through a 4-hour interview two weeks ago on C++ programming for the Trade Logic Developer internship. We set up a starting time based on my will, and they sent me the file. I finish it in four hours and send my work back. I did not leave any comments in my codes, because I do not know if they would like that. But I got my second round interview scheduled next week. They told me that it would be a 24-hour project.