| 1 | What is request deduplication in Next.js, and how does it help with data fetching? Next.js › Data Fetching | Next.js | Data Fetching | Advanced |
| 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 | If you are migrating a page from getStaticProps to the App Router, how do the equivalent data fetching patterns compare? Next.js › Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Next.js | Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Advanced |
| 4 | How do you fetch data inside a client component that needs to run in the browser? Next.js › Data Fetching | Next.js | Data Fetching | Beginner |
| 5 | How do you fetch data inside a server component in the App Router? Next.js › Data Fetching | Next.js | Data Fetching | Beginner |
| 6 | How do you fetch multiple pieces of data in parallel to avoid slow, sequential loading? Next.js › Data Fetching | Next.js | Data Fetching | Intermediate |
| 7 | How can you pass data fetched on the server down into a client component? Next.js › Data Fetching | Next.js | Data Fetching | Intermediate |
| 8 | 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 |
| 9 | How can Suspense be used directly for data fetching, beyond just code splitting? React › Suspense & Concurrent Rendering | React | Suspense & Concurrent Rendering | Advanced |
| 10 | 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 |
| 11 | 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 |
| 12 | 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 |
| 13 | How do you generate dynamic metadata for a page based on data fetched at request time, such as a product page? Next.js › Metadata API & SEO Optimization | Next.js | Metadata API & SEO Optimization | Intermediate |
| 14 | What does getStaticProps do in the Next.js Pages Router? Next.js › Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Next.js | Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Beginner |
| 15 | What does getServerSideProps do, and how is it different from getStaticProps? Next.js › Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Next.js | Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Beginner |
| 16 | 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 |
| 17 | How does getStaticPaths work together with getStaticProps for dynamic routes in the Pages Router? Next.js › Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Next.js | Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Intermediate |
| 18 | What are the different fallback options available in getStaticPaths, and how do they behave differently? Next.js › Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Next.js | Pages Router Data Fetching (getStaticProps, getServerSideProps & getStaticPaths) | Intermediate |
| 19 | 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 |
| 20 | What is the difference between using a resolver and simply fetching data inside a component's ngOnInit method? Angular › Router Guards & Resolvers | Angular | Router Guards & Resolvers | Beginner |
| 21 | How do you show a loading state automatically while a page's data is being fetched in the App Router? Next.js › Loading UI & Streaming with Suspense | Next.js | Loading UI & Streaming with Suspense | Beginner |
| 22 | 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 |
| 23 | How would you test a component that fetches data when it first appears on the screen? React › Testing | React | Testing | Intermediate |
| 24 | How would you manually trigger a not found response when a specific piece of data, like a product, does not exist? Next.js › Error Handling & Not Found Pages | Next.js | Error Handling & Not Found Pages | Intermediate |
| 25 | How do server actions automatically update the user interface after making a change to data? Next.js › Server Actions & Mutations | Next.js | Server Actions & Mutations | Intermediate |
| 26 | How would you test a server component that fetches data asynchronously? Next.js › Testing Next.js Applications | Next.js | Testing Next.js Applications | Intermediate |
| 27 | How do you type the data returned from an API call inside a server component to get proper autocomplete and error checking? Next.js › TypeScript with Next.js | Next.js | TypeScript with Next.js | Intermediate |
| 28 | How would you fetch data safely inside useEffect while avoiding a common bug called a race condition? React › Effects & Lifecycle | React | Effects & Lifecycle | Advanced |
| 29 | How do you fetch and share data across a layout and all of its nested pages efficiently? Next.js › Layouts & Templates | Next.js | Layouts & Templates | Advanced |
| 30 | What is Suspense in React and what basic problem does it solve? React › Suspense & Concurrent Rendering | React | Suspense & Concurrent Rendering | Beginner |
| 31 | What are API routes in Next.js and why would you use them? Next.js › API Routes | Next.js | API Routes | Beginner |
| 32 | How do you read query parameters and the request body inside an API route? Next.js › API Routes | Next.js | API Routes | Beginner |
| 33 | What is a dynamic route in Next.js, and how do you create one? Next.js › Dynamic Routes & Catch-All Segments | Next.js | Dynamic Routes & Catch-All Segments | Beginner |
| 34 | How do you render a fallback message when a list is empty? React › Conditional Rendering & Lists (Keys) | React | Conditional Rendering & Lists (Keys) | Intermediate |
| 35 | How do you read a dynamic value from the URL, such as a product id, using React Router? React › Routing | React | Routing | Intermediate |
| 36 | What is a React Server Component and how is it different from a regular component? React › Server Components | React | Server Components | Intermediate |
| 37 | 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 |
| 38 | 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 |
| 39 | What are the main caching layers in the Next.js App Router? Next.js › Caching | Next.js | Caching | Intermediate |
| 40 | How do client components and server components work together in the same page? Next.js › Client Components & Hydration | Next.js | Client Components & Hydration | Intermediate |
| 41 | How do you fetch draft or unpublished content differently from published content when Draft Mode is enabled? Next.js › Draft Mode & Preview Mode | Next.js | Draft Mode & Preview Mode | Intermediate |
| 42 | What is streaming in Next.js, and how does it improve the user experience? Next.js › Loading UI & Streaming with Suspense | Next.js | Loading UI & Streaming with Suspense | Intermediate |
| 43 | How do you use multiple Suspense boundaries on the same page to stream different sections independently? Next.js › Loading UI & Streaming with Suspense | Next.js | Loading UI & Streaming with Suspense | Intermediate |
| 44 | How do you use revalidateTag to refresh multiple related pieces of cached content at once? Next.js › On-Demand Revalidation Strategies | Next.js | On-Demand Revalidation Strategies | Intermediate |
| 45 | When would server side rendering be the better choice over static site generation or incremental static regeneration? Next.js › Rendering (SSR/SSG/ISR) | Next.js | Rendering (SSR/SSG/ISR) | Intermediate |
| 46 | 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 |
| 47 | 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 |
| 48 | How do Server Components and Client Components work together in the same app? React › Server Components | React | Server Components | Advanced |
| 49 | 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 |
| 50 | What are best practices for managing translation content at scale in a large, multilingual Next.js application? Next.js › Internationalization (i18n) in Next.js | Next.js | Internationalization (i18n) in Next.js | Advanced |
| 51 | How does the concept of state management differ in Next.js compared to a purely client side React application, given the presence of server components? Next.js › State Management in Next.js Apps | Next.js | State Management in Next.js Apps | Advanced |