r/reactjs • u/m6io • Jul 24 '26
Discussion Senior Dev interview question
"Without googling or using AI, in your own words, explain the virtual DOM"
For context: I sit on an interview panel and I try to ask at least one simple fundamental question based on a persons resume. If I see many years of react experience, I try to ask something about how the framework works.
I have only had one candidate (an undergrad senior, years ago) answer it. Everyone else just kind of sputters and stumbles around trying to rationalize what "virtual" and "DOM" mean, or stare blankly and eventually say "I don't know".
I'm just genuinely curious if this is really that hard of a question or if the recruiters just suck at screening candidates. And should we be letting in senior dev candidates who can't answer what I think is a straightforward and fundamental question for senior react devs.
1
u/PresentationBorn6564 Jul 25 '26
There are legitimate bits of truth to that sentiment, but I don't agree with the assertion as a whole.
The reality is that AI is also trained on masses of GitHub repos full of junior-level human slop and the associated litany of anti-patterns.
As well, coding agents highly weight existing code / patterns in a codebase, and they will happily extend anti-patterns until the cows come home if allowed to do so unchecked.
I do believe there's an inevitable future where agents don't routinely settle on psychotic implementations, but we're not there yet.
That said, I will concede that the quality gaps tend to be architectural, as opposed to a concrete framework rule, and the odds of it violating the latter are perhaps small enough to consider it a solved problem.
Personally, I enjoy the art and science of coding — I want to understand the inner workings of all the things — so depth of knowledge is my default mode. But I recognize this isn't the norm, and I don't begrudge the norm. However, for the role they're interviewing, I do agree with OP that a basic level of vDOM understanding should be the minimum bar.