DISCLAIMER: this is not a usual, quite dry (did I hear boring? 
) exposition of some more or less profound software construct, but quite personal and high-level, in that it talks about job interviews.
I had a unique experience today. Not only was it one of very rare occasions when I cold-call somebody for a job, but I was deemed as not having the required (or “matching” to use their words) skills. And, this after three phone interview sessions.
So, they probably wanted a database administrator? Or, perhaps they needed a Debian master to keep processes up and running? It could have been sustaining a legacy SAP system?
Nope. What they needed was someone who knew how to solve problems with a functional language. This was the reason I contacted them. This was a perfect fit for me!
But, the experts at that place considered my skills not to be even at a level where they would invite me for a personal meeting…
So, how can a seemingly rigorous interview process using highly intelligent people go so bad? A friend of mine told me that my failing to live up to their high standards was a clear sign of that process being defunct. I can only agree.
From now on you can disregard my 20+ years as professional (and many years as an amateur before that) developer and my Haskell/Erlang/LISP/C++ (for those not in the know, the latter language is quite amenable to functional programming) hacks and call me Junior Developer 
My advice to interviewers is:
- Do not ask about specific algorithms, and if you do, ask for more than one or two - the assumption that the candidate has been dealing with one specific algorithm, or one exact problem, the last few years is silly; the only exception is if that particular problem or algorithm is crucial to the job. I would not kill a candidate based on her not giving me the specifics about heap sort.
- If you ask a X question, expect a X response, where X is in
['big', 'deep', 'fuzzy']; I was asked a supposedly deep question in functional programming, i.e., what is a monad and was - presumably - expected to give a succinct answer - When trying to assess people’s skills, do not scan for predefined key words only; i.e., use your cognitive deduction apparatus to decide the level of that of the candidate’s; some meta cognition is sought after
To these interviewers defense, they might have used these seemingly mis-leveled questions in order to assess general problem solving skills and/or intelligence. If so, they did not do a very good job at it.
If anything, this taught me to put the interview questions at the right level and not look for some preset words, and disregard anything around those sought key words. Ah, and it also made me decide to kick some major functional ass