Explain how React, Svelte and Solid each decide what to update when a value changes. Then tell me what that difference means for a component that re-renders too often.
Answer it out loud before you open anything. The value of the flags below is in comparing them to what you actually said.
The situation behind the question
A team choosing a framework for a new data-heavy internal product, with a candidate who has used one of the three professionally.
What it is really testing
Whether the candidate holds a mechanism-level model of reactivity rather than framework preferences. The second half is the discriminator: knowing the models means knowing that "re-renders too often" is a problem that exists in one of them and largely does not exist in the others.