"Can you explain in depth how Google Maps works from a back end level?"

I was 19.

This was for an internship.

Needless to say, I didn't get it.

Wow! Either I'd just "backend gets coordinates from the browser and sends relevant images back." :)

Or just start to explain Ajax etc in general if it was a non tech.

What a bs question.

if you knew how google maps worked, you would've worked in google and you wouldn't be applying as an intern godamn it...

It is actually a great question. Except asking it for the position of an intern is an overkill.

@sterex is it? I would have thought that knowing the specifics of the backend of a certain service was a bit to narrow of a question. I'd have expected more along the lines of explaining concepts.

@Elkstorm Well, as I understand it, there is no right answer to that question - which is why it is a great question. Let me explain. When you ask someone how Google works, you'll get varied answers based on their education and experience (E&E). Now, when you ask that to a programmer who is expected to build something similar to Google, it will expose his level of E&E around the technical aspects of what goes into making what Google is, and does. Now, nobody is expected to know everything about Google - certainly it has taken several million man-hours* to create it. But, the programmer's E&E reveals which parts of the technology he understands and whether what he understands is something you are looking for in him. The answer, if not anything, reveals the interest level of the candidate.

Having said that, however great this question is, it isn't the only question that you should hire based on - but, this definitely sets the tone for further questions that follow.

* Personal estimate.

@sterex Thanks! All of a sudden it seems like a good question :) If it was indeed intended as a "tell me how you wold solve this" type of question then it's far better than I thought. My opinion is that Google map "isn't that complicated" as an idea. It is of course insanely complex. But more in terms of the monster load of traffic, raw data etc. Making something like it for just a few users could be sort of manageable. It's like how I understand the gearbox or breaks of my car but couldn't ever make a gearbox myself :)

…yeah it wasn't one of those. Apparently, Google Maps is run by a bunch of hash tables. And the position was for a front end Android Development internship…

@tulanator Did you try to find out (post-interview) what an acceptable answer was for the question? (According to the person interviewing you)

I'd have told them about the kd and quad trees and such... then about Dijkstra's I think... imagery is fed by satellites and labeled by humans. Stored in a multimedia database that uses point quad trees maybe.