[thekaleb]

I only bring up the prototype to determine if I would classify the interviewee as a senior JavaScript developer or not.

[bpicolo]

In modern times that's something you can easily throw far back in mindbank, because in practice using ES6 it almost never comes up, and it's super easy to do a quick refresher on the semantics. If I didn't know that interviewers tended to ask about it in frontend inteviews (because they totally do), would never bother to keep up to date with the semantics

[adrianhel]

Object.defineProperty('senior', { value: true, enumerable: false })

[scarface74]

There are two things I would expect even a mid level developer to know - how prototypical inheritance works and how “this” works in JS.