| 1 | How do client components and server components work together in the same page? Next.js › Client Components & Hydration | Next.js | Client Components & Hydration | Intermediate |
| 2 | How can you minimize the amount of JavaScript sent to the browser when using client components? Next.js › Client Components & Hydration | Next.js | Client Components & Hydration | Advanced |
| 3 | What is a client component in Next.js and when should you use one? Next.js › Client Components & Hydration | Next.js | Client Components & Hydration | Beginner |
| 4 | What is hydration in the context of Next.js and React? Next.js › Client Components & Hydration | Next.js | Client Components & Hydration | Beginner |
| 5 | What causes a hydration mismatch error, and how can you fix one? Next.js › Client Components & Hydration | Next.js | Client Components & Hydration | Intermediate |
| 6 | Why can't server components use hooks like useState or useEffect? Next.js › Server Components | Next.js | Server Components | Beginner |
| 7 | How do you decide whether a specific piece of a page should be a server component or a client component? Next.js › Server Components | Next.js | Server Components | Intermediate |
| 8 | How do styled components or other CSS in JS libraries work in the Next.js App Router, given the presence of server components? Next.js › Styling in Next.js (CSS Modules, Tailwind & Styled Components) | Next.js | Styling in Next.js (CSS Modules, Tailwind & Styled Components) | Intermediate |
| 9 | What data types and values can be safely passed as props from a server component to a client component? Next.js › Server Components | Next.js | Server Components | Advanced |
| 10 | Why is it important to never expose sensitive information like API keys inside client components? Next.js › Security Best Practices in Next.js | Next.js | Security Best Practices in Next.js | Beginner |
| 11 | What is a Client Component and when do you need one instead of a Server Component? React › Server Components | React | Server Components | Beginner |
| 12 | What is a server component in the Next.js App Router, and why is it the default? Next.js › Server Components | Next.js | Server Components | Beginner |
| 13 | 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 |
| 14 | How can you pass data fetched on the server down into a client component? Next.js › Data Fetching | Next.js | Data Fetching | Intermediate |
| 15 | How do you call a server action directly from a button click inside a client component, rather than through a form submission? Next.js › Server Actions & Mutations | Next.js | Server Actions & Mutations | Intermediate |
| 16 | How do you share state between multiple components that are not directly related, such as a shopping cart shown in both the header and a product page? Next.js › State Management in Next.js Apps | Next.js | State Management in Next.js Apps | Intermediate |
| 17 | What is the difference between a regular environment variable and one prefixed with NEXT_PUBLIC in Next.js? Next.js › Environment Variables & Configuration Management | Next.js | Environment Variables & Configuration Management | Beginner |
| 18 | How do you create a custom error page for a specific route segment in the App Router? Next.js › Error Handling & Not Found Pages | Next.js | Error Handling & Not Found Pages | Beginner |
| 19 | What is the difference between a layout and a template in the Next.js App Router? Next.js › Layouts & Templates | Next.js | Layouts & Templates | Beginner |
| 20 | What is local component state, and when is it enough for managing data in a Next.js application? Next.js › State Management in Next.js Apps | Next.js | State Management in Next.js Apps | Beginner |
| 21 | How do you write a basic unit test for a component in a Next.js application? Next.js › Testing Next.js Applications | Next.js | Testing Next.js Applications | Beginner |
| 22 | Why can you not use React hooks like useState inside the custom Document component? Next.js › Custom App & Document in Pages Router | Next.js | Custom App & Document in Pages Router | Intermediate |
| 23 | How does the global-error.js file differ from a regular error.js file in the App Router? Next.js › Error Handling & Not Found Pages | Next.js | Error Handling & Not Found Pages | Intermediate |
| 24 | How do you validate form data on the server before saving it, and show validation errors back to the user? Next.js › Form Handling & Validation in Next.js | Next.js | Form Handling & Validation in Next.js | Intermediate |
| 25 | How do you programmatically navigate to a different page in response to a user action, such as after a successful form submission? Next.js › Routing (App/Pages Router) | Next.js | Routing (App/Pages Router) | Intermediate |
| 26 | How do you protect a Next.js application against cross site scripting attacks? Next.js › Security Best Practices in Next.js | Next.js | Security Best Practices in Next.js | Intermediate |
| 27 | When would you reach for a dedicated state management library, like Zustand or Redux, instead of just using React Context? Next.js › State Management in Next.js Apps | Next.js | State Management in Next.js Apps | Intermediate |
| 28 | How do you use the useReportWebVitals hook to collect performance data from real visitors on your Next.js site? Next.js › Web Vitals & Performance Monitoring | Next.js | Web Vitals & Performance Monitoring | Intermediate |
| 29 | How would you combine parallel routes and intercepting routes together to build a modal that overlays the current page? Next.js › Parallel Routes & Intercepting Routes | Next.js | Parallel Routes & Intercepting Routes | Advanced |