| 1 | What does React.memo do and how does it help performance? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Beginner |
| 2 | How would you use the React Profiler to find which components are causing performance problems? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Advanced |
| 3 | What is the useCallback hook and how is it different from useMemo? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Intermediate |
| 4 | What is a simple real world example of when useMemo actually helps a React app? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Beginner |
| 5 | Why should you avoid overusing useMemo and React.memo throughout an entire app? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Intermediate |
| 6 | What is the useMemo hook and how does it help with performance? React › Hooks | React | Hooks | Intermediate |
| 7 | What is automatic batching in React, and how does it improve performance? React › Strict Mode & Concurrent Features | React | Strict Mode & Concurrent Features | Intermediate |
| 8 | How do you keep animations smooth and avoid hurting performance in a React app? React › Animation in React (Framer Motion & React Spring) | React | Animation in React (Framer Motion & React Spring) | Advanced |
| 9 | How does useDeferredValue help improve performance when rendering a large list based on user input? React › Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | React | Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | Advanced |
| 10 | Why can overusing Context sometimes hurt performance in a large React app? React › Context API | React | Context API | Advanced |
| 11 | What is Framer Motion and how does it make animating React components easier? React › Animation in React (Framer Motion & React Spring) | React | Animation in React (Framer Motion & React Spring) | Beginner |
| 12 | What is a simple real world example of when useTransition would make an app feel faster? React › Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | React | Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | Beginner |
| 13 | How do you render a list of items in React using the map function? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Beginner |
| 14 | What is React DevTools and how do you install it? React › React DevTools & Debugging | React | React DevTools & Debugging | Beginner |
| 15 | How do you create a clickable link to navigate between pages using React Router? React › Routing | React | Routing | Beginner |
| 16 | Why does a statically generated website often load faster than one that renders pages on every request? React › Static Site Generation (SSG) & Hydration | React | Static Site Generation (SSG) & Hydration | Beginner |
| 17 | What should you place inside a Suspense fallback, and what are some good practices? React › Suspense & Concurrent Rendering | React | Suspense & Concurrent Rendering | Beginner |
| 18 | What is the virtual DOM in React, and why does React use it? React › Virtual DOM & Reconciliation | React | Virtual DOM & Reconciliation | Beginner |
| 19 | Why does the virtual DOM make React apps feel fast even when data changes frequently? React › Virtual DOM & Reconciliation | React | Virtual DOM & Reconciliation | Beginner |
| 20 | How does React Spring differ from Framer Motion in the way it creates animations? React › Animation in React (Framer Motion & React Spring) | React | Animation in React (Framer Motion & React Spring) | Intermediate |
| 21 | What is code minification and why does a build tool perform it automatically? React › Build Tools & Bundlers (Vite, Webpack & CRA) | React | Build Tools & Bundlers (Vite, Webpack & CRA) | Intermediate |
| 22 | What problem does useTransition solve in a React app? React › Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | React | Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | Intermediate |
| 23 | Why is using an array's index as a key generally considered a bad practice? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Intermediate |
| 24 | How does automatic caching work in React Query, and why does it make an app feel faster? React › Data Fetching (React Query & SWR) | React | Data Fetching (React Query & SWR) | Intermediate |
| 25 | What does the dependency array in useEffect actually control? React › Effects & Lifecycle | React | Effects & Lifecycle | Intermediate |
| 26 | How do you clean up an effect in React, and why is it important? React › Effects & Lifecycle | React | Effects & Lifecycle | Intermediate |
| 27 | What are the main benefits of using Server Components in a real React app? React › Server Components | React | Server Components | Intermediate |
| 28 | What is hydration in the context of server side rendering, and why is it necessary? React › Server-Side Rendering (SSR) & Next.js | React | Server-Side Rendering (SSR) & Next.js | Intermediate |
| 29 | How would you show multiple separate loading states for different sections of a page using several Suspense boundaries? React › Suspense & Concurrent Rendering | React | Suspense & Concurrent Rendering | Intermediate |
| 30 | What is reconciliation in React, and how does it decide what actually needs to change on the screen? React › Virtual DOM & Reconciliation | React | Virtual DOM & Reconciliation | Intermediate |
| 31 | How would you preload a lazy loaded component before the user actually navigates to it? React › Code Splitting & Lazy Loading | React | Code Splitting & Lazy Loading | Advanced |
| 32 | When should you choose useTransition over useDeferredValue, given they solve a similar kind of problem? React › Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | React | Concurrent Hooks (useTransition, useDeferredValue & useLayoutEffect) | Advanced |
| 33 | How does SWR's stale while revalidate strategy work, and why is it useful? React › Data Fetching (React Query & SWR) | React | Data Fetching (React Query & SWR) | Advanced |
| 34 | How does React Hook Form simplify building forms compared to managing every field with useState manually? React › Forms: Controlled & Uncontrolled Components | React | Forms: Controlled & Uncontrolled Components | Advanced |
| 35 | How would you use React DevTools to find out why a component re rendered when you did not expect it to? React › React DevTools & Debugging | React | React DevTools & Debugging | Advanced |
| 36 | How does Recoil's atom based approach to state differ from Redux's single central store? React › State Management Libraries (Redux, Zustand & Recoil) | React | State Management Libraries (Redux, Zustand & Recoil) | Advanced |
| 37 | What are concurrent features in React, and how do they relate to Strict Mode? React › Strict Mode & Concurrent Features | React | Strict Mode & Concurrent Features | Advanced |