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1764 points fatihky | 1 comments | | HN request time: 0s | source
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lordnacho ◴[] No.12701486[source]
I'm amazed he knew things in such detail. I mean who would know just how long a MAC address is? Or what the actual SYN/ACK etc tcp flags are? You just need to know what they're used for, and if you need the specifics, you'll find out with a single search. He seemed to know that as well though. Kernighan for bit twiddling algos, that kind of thing.

It's a bit strange to have someone non-technical interviewing a techie. You end up with stupid discussions like the one about Quicksort. If you point out qs is one of several things with the same big-O, you'll probably also get it "wrong". But the real problem is that a guy who is just reading off a sheet can't give any form of nuanced feedback. Was the guy blagging the sort algo question? Did he know if in detail? Does he know what the current state of research on that area is? There's no way to know that if your guy is just a recruiter, but I'm sure even a relatively junior coder would be able to tell if someone was just doing technical word salad.

I wonder what would happen if ordinary people recruited for medical doctor jobs? Would you be comfortable rejecting a guy who'd been in medical school for 10 years based on his not knowing what the "funny bone" is? Wouldn't you tell your boss that you felt a bit out of that league? It's amazing you can get someone to do this without them going red in the face.

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tptacek ◴[] No.12701606[source]
I knew all these answers too, because I was a developer in the 1990s.

There is absolutely no purpose to knowing off the top of your head how long an ethernet address is, or even what system call will retrieve an inode (his bickering over stat() "filling in" rather than "returning" was bogus, for what it's worth). The top Google search result for each of these questions has the answer. Knowing these things isn't part of being a practicing programmer; knowing how to find out is.

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1. fefe23 ◴[] No.12702332[source]
Technically stat neither returns nor fills in the inode, because the actual structure of the inode can vary by filesystem, and the inode will contain more fields than struct stat.

In a recruiting situation, if the recruiter is going all "right and wrong" on the interviewee, they should know these dirty details.

I also disagree on the ethernet address length. You know how long IPv4 addresses are, you know how long IPv6 addresses are, why would it be so extraordinary to also know how long MAC adresses are?

I think it could be useful to find out in an interview whether the applicant knows stuff because they have actually implemented low-level code and gained an intricate understanding, or whether they just did used some high level APIs and were never interested in more details than "I have a handle right here, it does all I need". For some positions that would be an important distinction.

Personally, if I were interviewing people, I'd hire the guy that explains something to me that I did not know, but that I find interesting and would have attempted to understand, too.