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Google's “Director of Engineering” Hiring Test

(www.gwan.com)
1764 points fatihky | 13 comments | 13 Oct 16 15:15 UTC | HN request time: 0s | source | bottom
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lordnacho ◴[13 Oct 16 15:43 UTC] 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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1. segmondy ◴[13 Oct 16 15:56 UTC] No.12701620[source]▶
People that have been around know such things. At one point, Richard Stevens (RIP) was god. Every programmer had a copy of TCP/IP illustrated, Advanced Unix Programming and Unix Network Programming. If you wanted to do anything network, you had to write your own servers, you had to understand the details. The breath of knowledge was wide and the depth was just as deep. Ask around on HN, and you will probably be shocked how many that know such things. :-)
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2. henrik_w ◴[13 Oct 16 16:40 UTC] No.12702028[source]▶
UNP is excellent! Haven't opened it in a long time though.
3. pjlegato ◴[13 Oct 16 17:05 UTC] No.12702262[source]▶
And then, the world developed robust, well-maintained, open source libraries that do all of that for you. Now, in 99% of commercial software engineering, you don't actually need to know any of those details, in the same sense that you no longer need to know exactly how many transistors and diodes are used to build the adder on the CPU. It simply no longer matters in almost all cases. Your time is much better spent moving on to higher level problems.

If you're interviewing for the rare 1% case where the job will actually require you to tinker with a TCP stack, then by all means ask about those details. For 99% of programming jobs today, it's irrelevant trivia used as nothing more than an ego measuring device.

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4. noir_lord ◴[13 Oct 16 17:07 UTC] No.12702283[source]▶
Yep, I was doing network programming back in the late 90's and you pretty much had to have a good grasp of winsock and linux network calls and responses because the level of abstraction was much lower.

That said I can't recall any of that stuff mattering in the stuff I do for work for quite some time and most of it is a google search away.

That interview was just weird, it was like asking the boiler pressure for a steam train to someone who was a master engineer working on electric trains.

5. vvanders ◴[13 Oct 16 17:37 UTC] No.12702545[source]▶
None of that matters, until it does :).

I feel like I've seen 2-3 articles alone in the last month that has rediscovered head-of-line blocking and UDP. I'd say 1/10 engineers I talk to even know what cache aware datastructures are.

The thing that separates someone who can just string together whatever they find on npm to people who build real systems is this deep understanding. You're not going to need this for your standard LoB apps. However if you're in the business of building software you're definitely going to want people like this.

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6. ivanhoe ◴[13 Oct 16 17:37 UTC] No.12702548[source]▶
The amazing part here is that so many people still remembers all those little details. I still know how it works, but honestly I forgot all the details long time ago.
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7. pjlegato ◴[13 Oct 16 18:02 UTC] No.12702730{3}[source]▶
There's a vast middle ground between stringing together npm and rewriting the TCP stack. Most jobs that exist today fall firmly in that middle ground.

Trying to find the TCP stack engineer to build your app is like hiring a petrochemical engineer to do oil changes. If your pockets are as deep as Google's, yes, you can do that, but it's by no means necessary.

8. chetanahuja ◴[13 Oct 16 18:18 UTC] No.12702839[source]▶
"And then, the world developed robust, well-maintained, open source libraries that do all of that for you. Now, in 99% of commercial software engineering, you don't actually need to know any of those details.."

And that, ladies and gentlemen, is how we ended up with npm.

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9. chetanahuja ◴[13 Oct 16 18:21 UTC] No.12702861[source]▶
"Now, in 99% of commercial software engineering"

Whatever this thing... this... stringing together a 100 random github projects to get a webpage that kinda of works about 80% of the time is called -- please let's agree not to call it "software engineering".

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10. alasdair_ ◴[13 Oct 16 18:45 UTC] No.12703059[source]▶
Is TCP/IP Illustrated still the gold standard of books on the subject? I read it fifteen or twenty years ago and would like to finally own a copy (I borrowed it from the library), but not if there is something better.
11. HeyLaughingBoy ◴[13 Oct 16 19:53 UTC] No.12703521[source]▶
A lot of it depends on what you do day to day. A year ago, I knew what a MAC address was, but in an abstract way. Today I automatically know it's 6 bytes long because I look at them every day.
12. wst_ ◴[16 Oct 16 01:59 UTC] No.12716456{3}[source]▶
You are jumping into conclusions too fast. There are plenty of good software engineers who work with high level languages and technologies on a daily basis. You just have to know your tools, no matter what you do.
13. pjlegato ◴[16 Oct 16 23:47 UTC] No.12721750{3}[source]▶
This is a false dilemma. Npm-level programming and being able to rewrite the whole operating system from scratch are not the only two options.