The first round hr call is a combination of both tech questions and behavioral questions such as why IMC and experience, also asked about whether have other offers and decisions deadline. Takes 30 min in all.
30 min HR screen, resume explanation background and IMC culture fit check. Mostly just behavior questions and a very simple brain teaser (takes about 2 min to solve). Also asked why trading
One call with two employees who were traders. Discussed my experience and then IMC's directions of expansion. Did not do any specific problem solving or algorithms questions but I assume eventually would have had those interviews.