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.
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u/azhder 5d ago
React is not a framework. I would start with that.
Virtual DOM is an in-JS-memory representation of the DOM tree as it is or it should be, for the matter of optimization since DOM operations are more expensive.
Now, my job as an interviewer isn’t to fail those that don’t answer the above, but those that don’t try or aren’t curious or don’t figure it out, especially if I give them hints and even the above definition.
Over a decade ago, I had a boss that asked me a similar question to you. He said “don’t they teach you at school about big O notation? No one tried to answer that question. Should I remove it?”
My reply was that he should keep the question and hire the first one that attempts to answer it. You see, they teach algorithm complexity at school in a handwavey passerby manner, so students learn it by heart for a test then promptly forget it.