Two Front End Development Interview Questions No One Has Been Getting Recently + One I’m Afraid to Even Ask

Yes, I’m still helping out with screening candidates. I haven’t yet interviewed someone to replace me, but there’s still a week to go.

Anyway, we’ve had a couple of technical questions that candidates universally failed to answer. Why share them here? For starters I just want to know if we’re crazy to expect people to know these. I also like the idea of a kind of “easter egg” for candidates. If someone does enough research to find my blog and read this post, they’ve shown me something, even if it’s not the answer to one of the questions posed below.

The two that have surprisingly turned into stumpers (at least for the last five or six folks I’ve interviewed)

  1. What is hasLayout?
  2. What’s the significance of setting the body text to .625em?

And the bonus question that I want to ask, but don’t, because it’s kind of goofy to say out loud

  1. What’s “The Mark of the Web?”

Answers after the jump.

What is hasLayout?
hasLayout is a proprietary, read-only Microsoft property that has occasionally serious effect on the way that elements render, flow and react to events. Read more about it here.

I ask about it because it’s one of the first things I look at to when I’ve got a particularly strange IE6 bug.

At this point I don’t even need a really good answer for this one. I’d settle for vague recognition.

If they do answer it correctly, the natural follow-up is “name a way force an element to gain layout”

What’s the significance of setting the body text to .625em?
Simple answer- it sets the default font-size to 10px, which makes all kinds of calculations easier to make.

This very site uses the technique coupled with em-based measurements to make a site that scales nicely. I ask this one because the technique itself is pretty cool and simple knowledge of it (even without the experience of having used it) shows that the person has at least done some reading.
What’s “The Mark of the Web?”
<!– saved from url=(0014)about:internet –>
That’s “The Mark of the Web.” 🙂

Why is important? Setting the MOTW allows you to debug pages on your local machine in Internet Explorer without dealing with the dreaded “To help protect your security, Internet Explorer has restricted this webpage from showing active content” security bar.

Clearly very handy.

Read more about the MOTW here.


Personally, I’m surprised these have been as tough as they’ve been. Anyone else got any surprising stumpers?

8 thoughts on “Two Front End Development Interview Questions No One Has Been Getting Recently + One I’m Afraid to Even Ask

  1. The first two seem reasonable enough. Obviously you didn’t interview me to replace you. The third one is actually new to me though as I don’t do a lot of debugging of local files. Even knowing about it now I doubt it would get used very much.

  2. I just sent you an email.

    As for the MOTW, I use it when I’m doing JavaScript proof of concept stuff, mostly. It comes in really handy there.

  3. Let’s pick 2 completely random, farthest left corner, obscure tagging questions to ask our next FED candidates. That’s spending your time wisely showing off what YOU know (only by choice selection) and what 99 out of a 100 FED’s won’t know off the top of their head.

    Good use of everybody’s time.

  4. Those are random? The concept of layout in IE is a huge help when debugging cross browser CSS issues and, at the time this was written, that em measurement trick was quite popular. It’s since fallen out of favor, but it was useful at the time.

    Also, I WANT to hire the 1/100 and not the 99/100, so this line of questioning was obviously on the right track.

  5. So, they are not random, exactly, but they’re not the best way to filter out the 99/100. Consider the following case:

    You have two candidates. One of them a bang-up FED, the other who can’t do anything without asking other people on the Internet how they would do it. The bang-up FED knows what em is, how it works, the liquid layout, etc. Because it’s been a while since they’ve started a brand new page, they’ve forgotten what the default font size is. As with everything else, the more you learn, the more you forget – 16 is pretty arbitrary.

    The other guy is constantly making new pages – not experienced with existing systems. He looks up something like “how do you set the default font to 10px” on a forum, and gets many answers, including use: .625em.

    Based on the ability to answer that question, you might have just picked the much less experienced developer who just recently looked up such a basic question as how do you set a default font size.

    He’s not 1/100. The question doesn’t do what you want it to do. You could ask something like given that the default font is 16px, how would you set the default font to 17px, using em.

    This would filter out the guy who remembers that .625 number or .75 because it’s popular. It would include the guy who knows how em works and be able to do a little simple math, which FEDs have to be able to do.

    “Doing a little reading” is a double-edged sword. I’d much rather hire someone that can figure it out than one that HAS to read before he does anything. I’ve hired both kinds and am finding the avid blog followers are incapable of contributing their own solutions to problems, yet passionately defend some popular position. That’s fine if you want a code monkey, but if you’re trying to build something solid, they’re a distraction.

    My two cents. Take it or leave it…

  6. Based on the ability to answer that question, you might have just picked the much less experienced developer who just recently looked up such a basic question as how do you set a default font size.

    He’s not 1/100. The question doesn’t do what you want it to do. You could ask something like given that the default font is 16px, how would you set the default font to 17px, using em.

    It’s not like I was asking one question and the interview was over 🙂 These were part of a series of 20-30 questions that I would pull from during interviews. This random piece of luck you describe wouldn’t work for each of the questions in the dialog, so there’s be plenty of room for me to disqualify a candidate based on other answers.

    I don’t do this stuff anymore, anyway, so while the feedback is interesting it’s not actually feedback against anything current. I have a different set up that I use.

    And for what it’s worth, the team at Isobar was full of people who were “avid blog followers” and I’d put that team against anyone in the world. Of course, you can’t last very long at an agency without being able to do.

  7. The quality I’m always looking for is the ability to problem-solve small and large scale issues. There’s something about the blog following that encourages learning a new way of doing the same old thing, which is great as long as they can integrate and apply that information to the novel problem at hand (use it in context). However, just knowing a bunch of different ways to do the same thing for the sake of knowing it is useless.

    So, I guess what I’m really saying is that I wouldn’t necessarily exclude “avid blog followers” from the group that can figure it out. Maybe that’s the kind of team you had, and good for you. In my personal experience, the ones that talk a good game at interviews because they’ve been reading blogs all day long tend towards hacky non-original solutions. In other words, they can’t integrate.

    Perhaps, that’s really the point here. Not too many people are able to integrate complex information, and as everyone tells me, maybe I need to lighten up on the candidates.

    I’ll interview in several parts, including a part that gives them a real life problem, which can be solved with JavaScript, allowing them access to a computer with Internet. That way, they have the option of looking up what they don’t remember or scouring the forums and blogs for the answer.

    I know you were shocked by how few people are stumped by your questions. I’m more shocked at how few people can’t write 15 lines of code, WITH the Internet, in 30 minutes.

    Sigh.

    What setup are you using now, if you don’t mind me asking.

  8. *I know you were shocked by how many people were stumped by your questions. I’m more shocked at how many people can’t write 15 lines of code…*

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