There is probably some of that, no process is perfect... If nothing else, at least it's more objective than a more bias-prone personality fit approach. But it's also possible to practice - even 20+ years after University - if one wants to interview at Google or another company that uses those kinds of interviews. Reading a few blogs like this and some live interviews on a site like interviewing.io or some such will put you back to graph walks or sparse matrix multiplication in no time.