When a React application starts feeling slow, one of the first things developers often do is reach for useMemo, useCallback, or React.memo. We've all seen this pattern: A component renders more often than expected. The UI feels sluggish when inter...

Have you ever looked at a React component and thought: “Maybe I should wrap this function with useCallback, this calculation with useMemo, and the component with React.memo?” You're not alone. Memoization is one of the most frequently discussed Re...

You've probably heard about React Fiber. But why does it matter? And more importantly: > What problem was Fiber actually designed to solve? Fiber is React's internal architecture for representing and processing the work needed to update the UI. ...

Why doesn't React update the entire UI after every state change? Because React uses reconciliation. When a component renders again, React produces a new element tree. React then determines what changed compared with the previous result and prepare...

What Actually Happens When State Changes in React? When state changes, many developers think: setState → React updates the DOM That's a useful simplified model, but there's more happening in between. A better mental model is: State / Props cha...