Comment by mattlondon | Hacker News Reader

Comment by mattlondon | Hacker News Reader

This is why I love this question as a phone-screener for onsite interviews and stuff.

Sounds so easy, but there is so much depth in so many areas that people can drill into. If someone starts talking convincingly about the OS handling keyboard interrupts or about HTTPS certificate revocation during the TLS handshake explanation etc, you know they are probably worth bringing in for a face to face.

Someone bluffing will usually fail this really hard - "The browser connects to example.com and downloads the page." or something. Uh-huh. Maybe they talk about DNS ... Maybe they talk about a TCP connection ... Maybe they talk about retrieving the HTML and parsing it ... but even then, if they get that far that will be better than a lot of bluffers. If they have simply revised anticipating this question and can answer everything then congrats - they've just educated themselves in a lot of the core fundamentals :)

As an interviewer this question can easily take up a whole 30 min phone screener as good candidates get deeper and deeper.

> Sounds so easy, but there is so much depth in so many areas that people can drill into. If someone starts talking convincingly about the OS handling keyboard interrupts or checking for HTTPS certificate revocation during the TLS handshake etc, you know they are probably worth bringing in for a face to face.

If I ask you "what happens when you load a URL" and you start talking about the operating system's handling of keyboard events, I might get the impression you're hopelessly prone to bizarre and useless digressions.

I usually say something like "What happens if I type 'example.com' in my browser's address bar and hit enter?"

If someone goes wildly off-track and starts talking about the design of the mechanical switches in the keyboard or I am specifically interested in one area vs another then you can easily tailor it "Ok cool - lets skip ahead to the network aspects" or "lets say I've found the server and downloaded the HTML - now what?" etc.

That said, I often like to let people just talk in interviews unless I am really specifically trying to drill into one area and get specific evidence of specific skills. I might jump in with a "Ah - interesting. Tell me more about DNS" or whatever, but usually I find that the good candidates will have a lot to say, and the less-good candidates either say hardly anything, bullshit, or talk a lot but are not good communicators (confusing explanations/hand-waving/etc) ... or a combination of those things :)

I’ve more commonly heard the question phrased as “after you’ve typed a URL into the browser bar, tell me everything that happens when you press Enter”, which makes talking about key handling issues more reasonably in-scope.

I wouldn't consider it bizarre if a candidate has deep knowledge about something different than what I expected when I started. I'd consider that pretty normal actually, since most people don't work on the same thing.

I wouldn't consider it useless either, unless I'm hiring an engineer for a narrow focus on something (e.g. I want someone that knows BGP), but I've never done that.

I've found that the ability to learn is fungible.

> I've found that the ability to learn is fungible.

The ability answer a question effectively instead of exhaustively is important too, though, right?

Personally, I'd be more impressed by the candidate who answers this by first asking "is there a particular aspect or perspective of this task you're most interested in?", especially if they can highlight the broad aspects involved, and offer to drill down on any in particular.

Anyone who has such depth either:

1-Is a genius and has no problem getting a job, therefore doesn't have to jump through these hoops

2- Or is probably on the autism spectrum and might be hard to work with

What kind of programmer knows how the electrical engineering of a keyboard works and why should that be a deciding factor in getting a job in some crumby internet company that has no business working on hardware layer tech? Even as someone who has an understanding of these things, why would I entertain you with something as menial as how the browser does html parsing? If you want to know if I know what that is, just ask me what that is. Don't treat your candidates like lab rats.

> This is why I love this question as a phone-screener for onsite interviews and stuff.

Same here and I'm confused as to why this comment has been downvoted. It's a perfectly good question for level setting. You get an idea of how much the person knows about various aspects of the system without having to ask pointed questions that they may not know. Instead, they get to show you what they are knowledgeable about.

Reply on news.ycombinator.com