My Job Interview at Google (2008)

Re:My Job Interview at Google (2008) by s1k3s on Saturday May 09, 2020 @08:53AM (#23124320)

Yeah but here's the thing: I do understand the event loop, I understand the sync/async models in JS but I have very little knowledge of how setTimeout works in this context. That's because I've never used it, and I've never used it because the book that I read 15 years ago about JS said something like this: "Here's a function that allows you to run some code after some time. If you feel the need to ever use it, it means you're doing something wrong, therefore please never use it". This very vague explanation combined the lack of usage of it makes it pretty hard for a candidate like me to realize that you are actually asking a question about event loops. So my question is, if you want to see my knowledge about those things, why not ask some direct questions about it?

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Re:My Job Interview at Google (2008) by koonsolo on Saturday May 09, 2020 @09:26AM (#23124516)

I'm the kind of interviewer that would keep asking until you do know. I would actually start with asking about the event loop. Don't know that, no problem, what happens with setTimeout()? Don't know that, no problem, how does async, await work? Don't know that, why do we need WebWorkers? What happens with an infinite loop? How do events work? etc.

There are plenty of ways to see how this person came into contact with the event loop concept, whether in theory or in practice.

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Re:My Job Interview at Google (2008) by lostmsu on Saturday May 09, 2020 @12:35PM (#23126133)

Meh, I'm with previous commenter. I know what the event loop means, that JS is single threaded, and what setTimeout is supposed to do under normal circumstances. I consider the question stupid, moreover your answer to it is likely incorrect, because it depends on the implementation. I bet Node.js never interrupts the loop for example (and I never even done Node.js, it would just be a sane thing to do).

And yeah, you might agree on Node behaving differently, but that just proves the question is very bad. Even with "in browser" clause the answer can change tomorrow for all we know.

It is like asking about undefined C++ behavior in an intentionally very bad example.

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Re:My Job Interview at Google (2008) by koonsolo on Saturday May 09, 2020 @01:41PM (#23126702)

Then please enlighten me what frontend questions you ask in your interviews.

By the way, only 1 out of 10 frontend developers can answer what the event loop is, according to my experience.

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Re:My Job Interview at Google (2008) by lostmsu on Sunday May 10, 2020 @05:59PM (#23136663)

I am not saying understanding event loop is not mandatory for senior JS devs. It is just that your question is really obscure. Why not just ask what an event loop is and what are the consequences of that execution model?

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Re:My Job Interview at Google (2008) by koonsolo on Monday May 11, 2020 @03:20AM (#23139657)

Some JavaScript developers know the theory, but not all of them. At least you should know how it practically works.

So when you ask "What is the JavaScript event loop?", most will stare at you not knowing what it is. So then I jump to the practical side. They at least should have worked with either setTimeout, async/await and/or events. So then you start asking for practical consequences of the event loop, such as what happens with an infinite loop after setTimeout or await, or during handling of an event. That is a real practical example that they should know. If you don't then you don't know neither theory nor practice.

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Re:My Job Interview at Google (2008) by lostmsu on Monday May 11, 2020 @07:37PM (#23148705)

Practice can change tomorrow.

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