Well, without talking about the super vague title, that makes you start looking for optimized search algorithms just to get at the end a complete opposit of what you were looking at, the first interview was with HR a very unnecessary interview that I think should be removed even though it was with a quite a decent nice guy from czech but was anything but helpful for me or for the overall process of my application, the second interview was alright where it was technical tech oriented and more software engineering oriented where it was basically the equivalent of a whiteboard type interview where you have a problem and you need to propose pseudo-code solutions and complexity and what not, this interview was relatively the best interview, and then we come to the complete turn-off, a guy sitting in his chair at home copy-pasting a problem statement and giving you a time-frame of 10-15 minutes to come up with a code solution which has ABSOLUTELY nothing to do with the job offer itself, neither with data structures except for one, and yes you better write something that he will understand otherwise if he has never seen a function you used you're not getting a good feedback, more than that, if he asks you a question to which you already know the answer and you just clearly state that you are already familiar with the problem so you are just able to give a dynamic programming (a term he didn't understand) solution he will not like it, it's a "Why you aren't as dumb as other people we interview".