React Quiz: 10 Questions That Reveal Your Real Skill Level

React is the most commonly listed framework on developer resumes and one of the most commonly tested in interviews. But the gap between developers who list "React" and developers who actually understand React at a senior level is enormous. What separates them? Not whether they know the syntax. The difference is understanding why React behaves the way it does — the rendering model, the rules of hooks, when to optimise and when not to, how to think about state vs derived state. The concepts that separate junior from senior React developers Understanding the rendering model. React re-renders a component when state changes, when props change, or when a parent re-renders. Most developers know the first two. Many don't think carefully about the third — which is why they end up with unnecessary re-renders that hurt performance. Understanding hooks correctly. The rules of hooks aren't arbitrary restrictions — they exist because hooks are implemented as a linked list tied to render order. If yo