The 'puzzle' part is the best filter for them. Any professional programmer who has spent many years writing stock exchanges/banks/financial systems has not had

The 'puzzle' part is the best filter for them. Any professional programmer who has spent many years writing stock exchanges/banks/financial systems has not had any recent practice delving into the intricacies of the most commonly provided abstract data types. They probably have come across concurrency and synchronisation problems for which there is no simple one line answer so those questions don't get asked. I can't recall the last time someone told me 'this std::map or python dict()' is not fast enough, can you delve into it and make a better one. The skill is in the selection considering the big picture. Some recent graduate will have looked at all this recently and easily pass this barrier, get the job and move on in a short amount of time while they can. Is there a IT staff shortage? There probably is a shortage of people who don't spend their spare time on hacker-rank or don't really feel motivated enough to spend a day on a bullshit contrived project. There are plenty of you people who don't mind.