Unlike my sibling saying it's "pull out of thin air", I think this is an opportunity to actually do the opposite: Ask questions back!
I have no idea how to guess that. I don't know what kind of information Google stores in it's "index". What exactly do they mean by "index" even? I need more input. I can ask the interviewer questions and start a discussion!
Of course it's possible that the interviewer really just wanted to be a smart-ass and expected me to "just have an answer" and else fail me. But then I don't want to work there anyway. Having an actual discussion, as if we were just working together and had to 'solve' whatever problem at hand is great.
Because these kinds of questions do not tell you anything about the person’s ability as a developer, a leader or give you any insight into the ability to be innovative. As others have noted, it simply measures their ability to make basic assumptions and then do math, plus bullshit your way through a discussion. Might be perfect for hiring product managers tho. /s ;)
Like my sibling reply says, I think you didn't read past my first word in the reply. The "why". That was rhetorical.
My entire point was basically that it actually isn't about assumptions at all. If you just assume when I ask that question this tells me you're out as a developer I want to hire. Nobody can build proper software by just assuming the first thing that comes to mind and bullshitting.
You have to show that you can take a totally ambiguous and open question and show me that you can systematically try to find out as much information as you can in a reasonable amount of time to verify your assumptions or at least make them less assuming. Of course (a d this can happen when solving a real problem too) it might be that you cannot accurately measure some input you need and you will have to make assumptions. But you will want to try and you will want to have divided your problem into lots of smaller parts such that the part where you still have to assume is only one small part and you want to be very explicit that this part is still an assumption only which you will have to verify or improve upon as you actually implement something. You do have to start at some point, otherwise it's analysis paralysis.
And no this has nothing to do with a PM. They are notoriously bad at the above approach and instead will just assume the first best thing and bullshit their way through with that for as long as they don't get caught (no /s there but my experience with 80+% of PMs)
Fair enough, but I get that signal from asking them an actual system design question, or even a coding problem. It's really a waste, which is better than "awful", I guess. :)
But you don't have to make assumptions! I think this is the important bit: you are supposed to ask questions back until you are confident enough about your answer. You should highlight that you are able to work with customers that want something without knowing what they want.
Agreed that it isn’t ideal, but about “awful” specifically - I’m not too sure. I would never ask such a question but I would assume the intent is just to find out how you think and not to get you to spit out a number. Would it be fun if the interviewer worked together with you to approximate it?
Yup that was exactly the case. A fun discussion that involved estimating sizes of web pages, number of web pages, the effect of compression, the effect of deduplication, etc.
(I was in fact asked a long time ago in an interview to estimate how much disk was needed to store Google's search index.)