Favorite Front-end/UI developer interview questions?

• Please estimate how long it would take to build this webapp based on these requirements?
• What if you only have half an hour?
• Let's build it. Now. Together.

This gives us insight in how you handle challenges and if you can prioritise the features that bring value.

A lot of these are great but come from a line of 'traditional' / 'booksmart' thinking..
which is great for probing and making sure candidates have the knowledge behind knowing how to answer the question... but for a lot of these i'd accept an "i don't know, but i'd look at the API docs for this method/class and learn how to manipulate the js object or function to my need"

yakno? js evolves so quick; knowing the fundamentals of OOP + quick absorption of docs + knowing how to quickly iterate = a winner

Assuming they'd be expected to know about the "virtual DOM", popularized by React and others, asking why the virtual DOM is needed and how it generally works high level.

"Do you agree that React is massively overused and is basically like using a sledgehammer to crack a nut in most cases?"

What is the difference between the focus and the caret ?
(Actually I use that question when I am grilled by people who know a js framework very well, have very limited frontend knowledge and try to establish a position of dominance. )

Also if somebody was asked a UI design question- please put that up as well! Christina, can you ask for this in your post as well? Some companies give you a days time to design a mock website. Such questions would help too!

I was given an object and asked to create a copy.
I happily said Object.assign...
So these there the follow ups that screwed me over-

1. What if it has nested objects, then Object.assign wont deep clone it. (where i answered with a loop to resolve this issue)
2. What if there is a cyclic dependency? (I was stuck, but the interviewer insinuated to the tortoise-hare algo of two pointer solution to crack the cyclic dependency, although i still dont think that will help).

Note- I was to answer in VanillaJS, so answers like Lodash deep clone wouldnt work.
Anyways, I went back and learnt a lot while exploring this concept.

How would you make a basic grid?

Oh wow, I realized that I know the answer to ALL these questions!! That's amazing!

1. The famous setTimeout question.(event loop)
2. Variable and function hoisting.