My first Frontend Interview

Today, after 4 months of studying, I had my first Frontend Developer interview.
The position was not for a Junior on, and the process included a first stage of 5 questions, and a second one of practical example over HTML/CSS and JS.
I consider myself to have a good knowledge…not a deep one of course. I went in the interview kind of calm, and confident that in case of not knowing the answer in specific, I could easily search…
The process was pretty straight, 5 quick questions to answer, no further discussion over what I did, what I am doing and blablabla…


  1. (HTML) - explain “placeholder” attribute.
  2. (CSS) - explain "Z-index"
    3 (JS) - difference between APPLY() and CALL()
    4 (JS) - Adding a number and a string, result is…?
    5 (JS) - how cookies translate/move to the browser.

To pass to the next stage, I had to answer 4 out of 5…I failed, not being able to fully explain 2, 3 and 5.

About the interview some comments I have:


  • I really understood what to focus in the future.
  • I understood the importance to FULLY understand the “behind the hood” Javascript engine…I need to review again and again YDKJS and Anthony Alicea course at Udemy.
  • I am more than motivated since I am not far away from the first step…things are moving and time will give me more knowledge and experience.


  • no conversation at all, on what I am studying, what I want to study…I think beside firing 5 questions like this, the interviewer should try to “know” the person in front of him.
  • where I could not give fully explanation on the above questions, it was not because I was not aware, just I did not know the details. At the moment, during a project or a challenge, I can Google and find the right syntax or the right instructions. Of course, in few months, the amounts of technical info that I have in top of my head are limited, but does not mean that i was not aware.
  • Although it was NOT a Junior position, the questions I found kind of hard…but fair, since I agree that once you know JS upside-down, “you can learn any library in one day”.

In conclusion, good experience…and I know better the direction to take, it is just about time.


First congratulations, in my mind even just getting as far as a job interview is plain amazing.

But I’m surprised because though I’m really a beginner, really struggling at the moment and fighting not to give up, I don’t find the questions difficult at all!

I’m not saying I would have been able to answer all of them accurately but it all seem pretty basic to me - except the cookie thing because I’ve never even looked into it and anyway I prefer the word biscuit - but even that doesn’t seem an advanced topic?

Like I said, well done for making it that far.


Don’t worry! You will get there!
I’m really surprised you got an interview like this. Was it at a technology company?

Most of my experience with interviews have been with questions like: ‘what have you built’? and ‘what problems have your faced in a project?’

There are lots of great resources out there for technical questions, just hop on one of those. Remember to practice the concepts as well.

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Over the years I’ve found that most interview processes, tech or not, to be complete crap. When they start asking hypothetical questions it tells me that they don’t know what they’re doing and have no real idea of what they’re looking for in a candidate. A lot of the methods people utilize in interviews are based on unsubstantiated pop psych - a lot of which has been proven to be ineffective at reliably predicting someone’s candidacy. Frankly, most companies would see the same hiring results if they picked a random name from a hat.

That being said, any job in coding at least requires a basic understanding of it and the questions they asked you are pretty simple. You should take the time to learn the answers to each one if for no other reason than to grow as a developer.

Don’t get discouraged. There’s a good chance you could’ve got them all right and still not gotten the job. Failing interviews and getting passed over for jobs is just how the world works. Try focusing more on entry level and junior positions in the future and you’ll probably have your first front end development job in no time.


Yes, more motivated than ever, and happy to have this opportunities that just few months ago were complete utopia.
It was a tech startup, kind of well know…and I agree, those questions I need to know.
Said that, I was expecting a more constructive interview, bit more colloquial, but I guess they have their way to filter the candidates.
In four months, I have learnt so much, but of course, I do not have the confidence to answer “in word, with examples”…usually I google them, and I can build on top in my projects. In a couple of months, when I will finish the study plan, I will have more time to focus on certain topics (ie. Javascript)…so I will be able to answer those type of questions easily. On the other hand, I can look at more Junior positions.
Advice to myself and to the others in the same boat…love coding, learn learn and apply, the more you learn to more you improve the skills, the more you can show them, the more the “luck interview factor” is necessary, and the more your skills will speak for you.


Hey, thanks a lot for sharing your experience, especially for listing the interview questions. It’s always interesting to read what kind of questions are being asked :wink:

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First off, thanks for sharing. I would’ve failed that questionnaire myself, but now you and I and anyone else in our shoes knows what to focus on.

Second, keep your head up. The only way from here is up.

How did you get the interview in the first place? Was it a connection or an application that got you in the door?

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I agree, it can just get better…
It was a regular (not Junior) position for Frontend Engineer, requiring HTML/CSS and deep JS.
I tried applying it and sending my repositories…I could get the foot on door, hoping for a more “soft” interview…
The interviewer was nice, giving me tips on what to focus, motivating me in continuing learning, and offering me the opportunity to contact him again when I d be more ready for such a test.

Can someone answer question 3 and 5?.
Thanks!great experience thank you for sharing.

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  1. (HTML) - explain “placeholder” attribute.

  2. (CSS) - explain "Z-index"

3 (JS) - difference between APPLY() and CALL()

4 (JS) - Adding a number and a string, result is…?

5 (JS) - how cookies translate/move to the browser.


Hey , thank you very much for sharing your experience , it gave us “beginners” alot of insights .
about the questions, i found them deep and not what most online javascript tutorials offers , i wish you the best luck for your next interview.


Thanks for sharing your experience and good luck!

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I hope you at least feel proud of yourself for having the confidence in yourself to commit to an interview! In my eyes, that’s a huge hurdle in itself! I am new to front end development so I can’t say either way in terms of those interviews. I have seen guys when I was in construction though who I knew for a fact were skilled but when it came to the interviews, struggled. So, I guess my point is that even if you hit a couple bumps, you had enough courage to go to the interview in the first place and didn’t get the typical, “What if I’m not good enough” attitude! Well done! It’s not the only interview and I’m sure you’ll nail the next one!

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Way to take the plunge, dude! Kudos!

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Well Good Luck for the Next Interview. And Thanks for Sharing your experience, its helpful. :slight_smile:

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I really like the easy rule for remembering the difference between “apply” and “call”. “A-pply” receives an Array as an argument. This is it.


Thank you so much for sharing. Hoping to be in a Full Stack position in 6 months myself. Be proud of yourself for reaching for your goals. I like your story because you did not lament your failure, but instead treated it as an opportunity to learn. Take care!


I will go for the web cookies. I think cookies are pieces of data you get by HTTP when you visit a website (they are generated randomly, and each website gets its own specific cookies). Those pieces of data are stored in computer. When you visit the website again, the browser uses those cookies as a reference. By reference, I mean like since each web page gets its own specific cookies, by looking at the cookies, the browser can know which web page corresponds to which cookies. Cookies can also help the browser know whether the user is signed in in a particular website (because the browser can see the cookies that reference your logging in).
When you delete browser history, you also delete the cookies, and that’s why you get logged out of all your accounts. The browser can’t see anything telling it that you are logged in.

For .apply() and .call() I need to read more. I still use them interchangeably, especially when I am doing this binding. I would say they pretty much work the same way, but that’s mostly likely untrue when you did deep into details.

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Thanks for sharing with us. This is encouraging. Indeed YDKJS deserves re-reading. Remember Nabokov’s quote: “There is no such a thing as reading. Only re-reading.”


Hey, I just want to say that I am currently taking JavaScript: Understanding the Weird Parts by Tony Alicea on Udemy. And the primary goal of the course is exactly as you said— to get a clear understanding of the “behind the hood” Javascript engine. In fact, in my progress so far, he has already answered #3 and #4 of your interview questions, and I’m only half-way through the course. I would recommend it if you can afford to shell out $10-20 for it. I’ve seen it the course go for as low as $10 or $15 at times.

Question #3)
CALL() takes a regular listing of parameters
and APPLY() requires the parameters to be in an array.

Question #4)
When adding a string and a number, coercion happens. Coercion: converting a value from one type to another. This happens because JS is dynamically typed.

var num = 1; // a number value var str = '5'; // a string value console.log(num+str); // result will be 15 because the 1 will be coerced to a string value

Hope this helps you.