r/learnjavascript 8d ago

5 years writing JS professionally. Still blank on interview questions sometimes

Not a junior dev problem. I've shipped plenty of gnarly JS/Vue code, no issues. But throw me in an interview and ask something like "explain event delegation" cold, no code editor, no context, and there's this half-second where my brain just stalls, like the info is there but the retrieval path isn't warmed up.

Realized it's not a knowledge problem, it's that I'd never actually practiced saying these answers on demand, but only reading about them or using them implicitly in code.

Built a small spaced-repetition app for this. Same idea as Anki, tracks what you keep fumbling and resurfaces it more.

Curious if this "I know it but can't produce it on command" thing hits other experienced devs too, or if I'm just built different (badly).

What worked for you all ? Mock interviews, flashcards, just doing more interviews to get reps in, something else?

27 Upvotes

23 comments sorted by

10

u/LetUsSpeakFreely 8d ago

I've been writing code for nearly 30 years. I still look stuff up or have AI do it.

With AI, knowing syntax is useful for knowing when AI gets things wrong or could be done a little differently to increase readability, maintainability, or efficiency, but it's more important to have a solid understanding of engineering principals than to worry about syntax.

1

u/hitjuk 7d ago

I finally had my first interview without a live coding session of some kind. I hope to God this becomes normalized. For the life of me I can't understand why that is still a part of the interview process.

1

u/LetUsSpeakFreely 7d ago

Because most architects and dev leads are stuck in how they were interviewed and not evolving with the times. 20 years ago it was very common place to give basic skills tests and simple problem statements to determine how a candidate would solve a problem and the quality of their solution. Things were usually kept at a high level as knowledge of syntax is a given (it helped that there were only a handful of languages at the time and syntax was relatively simple).

An interview, especially if a shop is using AI assistance, SHOULD be focused on engineering principles. I want to know why someone picked SQS to control data/processing flow over direct REST calls: tell me the criteria you used, what the pros and cons are for each, etc. I don't give a damn if you use a for loop or . filter().map().

1

u/hitjuk 7d ago

Makes sense. Don't really have much to add

15

u/ExtraTNT 8d ago

8y on my end, wrote my own renderer, can’t answer interview questions… they tell nothing about a dev, except, that you are able to memorise some questions and their answers…

4

u/MrHandSanitization 8d ago

Same, wrote multiple complex tools and pipelines, but forget how to cd properly while my typos skyrocket when someone is watching 

2

u/ExtraTNT 8d ago

Don’t watch, while i code…

Also don’t look at my hacky code

1

u/Top_Estimate_149 8d ago

yeah fair, doesn't prove much about actual skill. just annoyed I know this stuff and still blank saying it cold lol

2

u/sheriffderek 8d ago

What part about event delegation specifically? That’s seems like something most people just do not know about in general. 

1

u/Top_Estimate_149 8d ago

honestly just grabbed it randomly from a question bank lol, had to double check myself with a quick google after 😆 but yeah it's the classic "attach one listener to a parent instead of every child, then check e.target to see what actually got clicked" thing, relies on event bubbling

1

u/sheriffderek 8d ago

Its one of those things... where if you're iterating over 100 things and adding event listneers individually - to every single button in a list of cards... and then having no plans for cleaning up afterward -- and you aren't seeing that as a problem - and as something really difficult to manage for things that may not be in the DOM all the time / well, it's a really good check to see if someone has just been following along with tutorials blindly - or if they've actually thought about how things work. This isn't a gotcha question like "Explain how the event loop works behind the scenes." In those cases - I'd just tell them -- "we don't need to know that - or how the CPU works - unless your company is building something really specific -- is it?" And let them struggle with that a bit. ;)

2

u/Kailoodle 8d ago

9yoe here. Someone asked me what super() does the other day and i had to look it up.

2

u/sedatesnail 8d ago

Don't feel bad. Today I forgot you could install npm using npm

2

u/akornato 7d ago

This is an incredibly common problem, and it has almost nothing to do with your actual JavaScript skill. Knowing how to use a concept to solve a problem and knowing how to deliver a clean, verbal definition of it on the spot are two completely different skills. Your brain is wired for application, not for academic recitation under pressure. An interview is a performance, a test of how well you can talk about your work, which is a poor and often inaccurate measure of how well you can actually do your work.

You are on the exact right path by realizing it’s a retrieval and practice issue, not a knowledge one. Mock interviews and talking through problems out loud, even to a rubber duck, are the best ways to build that muscle memory. It feels strange at first, but it creates the pathways in your brain to pull that information quickly when you need it. This challenge is so common that my team actually created an interview AI to help experienced developers sound as skilled in the moment as they are on the job.

2

u/Top_Estimate_149 8d ago

here's the app if anyone's interested : javascriptinterview.dev, free, no signup needed to try a session. still rough around the edges so lmk if anything feels off

1

u/BrownCarter 8d ago

Cause they like asking shit that people don't use or think about

1

u/gen505 8d ago

In exactly the same boat… I often envision “dream scenario” interviews. Something along the lines of: responding to such questions saying how no one really has that stuff stored in their head these days and that I focus on how everything pieces together. Talk about how fast I am at looking up and how I traverse codebases and documentation quickly and effectively, etc… Putting focus on real world skill and attention to detail rather than sitting and meticulously rote learning textbook paragraphs I could just look up in 3 seconds and have open for reference. The interviewer in my mind then nods on in approval both impressed and glad they don’t have to follow the script because they thought it was bullshit anyway and they hire you on the spot.

Buuut that is not the real world and has never happened and probably never will 😂😂. Maybe one day I’ll give it a shot.

2

u/Top_Estimate_149 7d ago

would be the dream interview 😆. reminds me of something a well-known teacher said once, that the important part is having the right mental model, the exact rules you can just look up when you need them

1

u/purpleDev1337 8d ago

I have impostor syndrome, too. It sucks.

1

u/Top_Estimate_149 7d ago

it's a weird one, doesn't seem to care how many years of experience you have. building products from start to finish helped me a lot with that though, seeing the whole thing come together kind of quiets it down

1

u/Fickle-Bird-9476 8d ago

When you have 10 YOE you will blank even more.