All that is true, but there's a simpler fix. If they're not reusing each others' questions then it should be significantly harder. Nobody should be using "reverse a linked list" anymore - that's a really old one.
That's not a simple fix. If you don't use "reverse a linked list" anymore, then you start asking increasingly harder and harder questions, and the bar gets ridiculously high, to the point where everyone needs to know how to solve NP-class problems within 45 mins. And even then the system still can be gamed by simply memorizing more and more questions. It's a lose-lose situation.
You just have to make the problems so diverse (not necessarily hard), that genuinely understanding the solutions is the easier strategy than rote learning.
Can you give me an example of a question that isn't located in glassdoor.com and is "diverse but not hard". As far as I'm concerned, the bar is already ridiculously high to the point where I feel like the only people that get jobs are the ones who randomly get lucky enough to get 3 or 4 interviewees that ask easy questions.
There are people I know personally that have gone through every single one of the 1000+ Google interview writeups in glassdoor in order to prepare for interviews. One of my former co-workers showed me 10 pages of questions he distilled from glassdoor of various questions that were reported, and he memorized the answers to all of them, ranging from "find the common descendant of two nodes of a directed graph", to programming an AVL tree on the spot, to pure dynamic programming questions.
If they asked these types of questions 15+ years ago when I started, there's no way I could have gotten into programming. Even now, the caliber of those questions are simply too hard for me unless I sit down days before the interview to get the answer. There's no way I would be able to figure those out within 45 mins let alone 2 hrs, and I'm not dumb. It's ridiculous the level of expectations people have these days.
> Can you give me an example of a question that isn't located in glassdoor.com and is "diverse but not hard".
Sorry, `diverse' is an attribute of the distribution of questions you ask. Not of any single question. If for each interview you take a random question from glassdoor.com (and perhaps even tweak it a bit, if you feel like it), that might even meet the definition of a diverse but not too hard selection. (Unfortunately, I know almost nothing about glassdoor.com, and what kind of questions they have.)
When applied to me the problem is probably the other way round: I like all those silly questions and solve them in my free time for fun. (I did study mathematics, because I like this kind of thing.) But honestly, that doesn't help me much in writing non-trivial programs, and there's a bunch of people I know that are worse in those interview-type questions, but better at developing software.
But the clever thing is the work required to answer these questions is a filter in itself. Firstly it filters for the seriousness of the interviewee - have they done their (days of) preparation? And even then only a few people will have he ability to actually understand the quiz questions, and even if the answers are there in front of them.
The only problem is the filter for being good at cramming interview questions is not quite congruent with the filter for being a good programmer/developer/engineer/$role_youre_hiring_for.
