| 1 | What problem do libraries like React Query and SWR solve compared to fetching data with plain useEffect? React › Data Fetching (React Query & SWR) | React | Data Fetching (React Query & SWR) | Beginner |
| 2 | Why is it usually better to use a data fetching library instead of writing your own fetch logic in every component? React › Data Fetching (React Query & SWR) | React | Data Fetching (React Query & SWR) | Beginner |
| 3 | How would you handle a mutation, such as creating a new item, using React Query? React › Data Fetching (React Query & SWR) | React | Data Fetching (React Query & SWR) | Intermediate |
| 4 | 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 |
| 5 | 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 |
| 6 | How would you refresh data shown on a page after a server action successfully changes something in the database? React › Server Actions & Data Mutations | React | Server Actions & Data Mutations | Intermediate |
| 7 | How does data fetching work differently in a Next.js Server Component compared to fetching data in a regular client rendered React app? React › Server-Side Rendering (SSR) & Next.js | React | Server-Side Rendering (SSR) & Next.js | Advanced |
| 8 | How can Suspense be used directly for data fetching, beyond just code splitting? React › Suspense & Concurrent Rendering | React | Suspense & Concurrent Rendering | Advanced |
| 9 | How would you write a custom hook to fetch data from an API and share that logic across components? React › Custom Hooks | React | Custom Hooks | Intermediate |
| 10 | How would you test a component that fetches data when it first appears on the screen? React › Testing | React | Testing | Intermediate |
| 11 | How would you fetch data safely inside useEffect while avoiding a common bug called a race condition? React › Effects & Lifecycle | React | Effects & Lifecycle | Advanced |
| 12 | What is Suspense in React and what basic problem does it solve? React › Suspense & Concurrent Rendering | React | Suspense & Concurrent Rendering | Beginner |
| 13 | How do you render a fallback message when a list is empty? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Intermediate |
| 14 | How do you read a dynamic value from the URL, such as a product id, using React Router? React › Routing | React | Routing | Intermediate |
| 15 | What is a React Server Component and how is it different from a regular component? React › Server Components | React | Server Components | Intermediate |
| 16 | How do middleware, such as Redux Thunk, help handle asynchronous operations like API calls in Redux? React › State Management Libraries (Redux, Zustand & Recoil) | React | State Management Libraries (Redux, Zustand & Recoil) | Intermediate |
| 17 | What is incremental static regeneration and how does it solve the problem of static content becoming outdated? React › Static Site Generation (SSG) & Hydration | React | Static Site Generation (SSG) & Hydration | Intermediate |
| 18 | How would you build a custom hook that debounces a fast changing value, such as text typed into a search box? React › Custom Hooks | React | Custom Hooks | Advanced |
| 19 | How would you safely display user generated HTML content, such as a rich text comment, without exposing your app to XSS attacks? React › Security in React (XSS & dangerouslySetInnerHTML) | React | Security in React (XSS & dangerouslySetInnerHTML) | Advanced |
| 20 | How do Server Components and Client Components work together in the same app? React › Server Components | React | Server Components | Advanced |
| 21 | How would you decide between static site generation and server side rendering for a specific page? React › Static Site Generation (SSG) & Hydration | React | Static Site Generation (SSG) & Hydration | Advanced |