| 1 | What are the rules you must follow when writing and using hooks, including custom hooks? React › Custom Hooks | React | Custom Hooks | Intermediate |
| 2 | What is a custom hook in React and why would you create one? React › Custom Hooks | React | Custom Hooks | Beginner |
| 3 | How is a custom hook different from a regular helper function? React › Custom Hooks | React | Custom Hooks | Beginner |
| 4 | 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 |
| 5 | 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 |
| 6 | What are the downsides of higher order components that led many developers to prefer custom hooks instead? React › Higher-Order Components (HOCs) | React | Higher-Order Components (HOCs) | Advanced |
| 7 | 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 |
| 8 | What are hooks in React and why were they introduced? React › Hooks | React | Hooks | Beginner |
| 9 | What are the rules of hooks, and why do they exist? React › Hooks | React | Hooks | Advanced |
| 10 | How do lifecycle hooks in Auto Scaling Groups let you customize instance launch and termination behavior? AWS › Auto Scaling Groups | AWS | Auto Scaling Groups | Advanced |
| 11 | 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 |
| 12 | How do you create and use a custom Context in React step by step? React › Context API | React | Context API | Intermediate |
| 13 | How would you build a custom hook to make using a specific Context simpler and safer? React › Context API | React | Context API | Intermediate |
| 14 | How does the async pipe simplify working with observables directly in an Angular template? Angular › Pipes (Built-in & Custom) | Angular | Pipes (Built-in & Custom) | Intermediate |
| 15 | How would you rewrite a render props component as a custom hook instead? React › Render Props Pattern | React | Render Props Pattern | Advanced |
| 16 | How do you make a custom React component keyboard accessible? React › Accessibility (a11y) in React | React | Accessibility (a11y) in React | Intermediate |
| 17 | How do you handle CRDs and their custom resources syncing in the right order? ArgoCD › Sync & Health | ArgoCD | Sync & Health | Advanced |
| 18 | How can you customize health checks for third-party or custom resources? ArgoCD › Sync & Health | ArgoCD | Sync & Health | Advanced |
| 19 | How would you animate a button so it grows slightly when a user hovers over it? React › Animation in React (Framer Motion & React Spring) | React | Animation in React (Framer Motion & React Spring) | Beginner |
| 20 | 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 |
| 21 | What problem does the Context API solve in React? React › Context API | React | Context API | Beginner |
| 22 | 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 |
| 23 | 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 |
| 24 | What is the useEffect hook used for in React? React › Effects & Lifecycle | React | Effects & Lifecycle | Beginner |
| 25 | What is internationalization in a React app and why is it important? React › Internationalization (i18n) in React | React | Internationalization (i18n) in React | Beginner |
| 26 | How would you let a user switch the language of an app using a simple dropdown menu? React › Internationalization (i18n) in React | React | Internationalization (i18n) in React | Beginner |
| 27 | What is a simple real world example of when useMemo actually helps a React app? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Beginner |
| 28 | What is a simple real world example of the render props pattern being useful? React › Render Props Pattern | React | Render Props Pattern | Beginner |
| 29 | What is Redux and what problem does it solve for larger React apps? React › State Management Libraries (Redux, Zustand & Recoil) | React | State Management Libraries (Redux, Zustand & Recoil) | Beginner |
| 30 | Should you leave Strict Mode enabled in your app permanently, or only use it temporarily? React › Strict Mode & Concurrent Features | React | Strict Mode & Concurrent Features | Beginner |
| 31 | What is React Testing Library and how does its approach to testing differ from testing internal implementation details? React › Testing | React | Testing | Beginner |
| 32 | What is the difference between a unit test and a component test in a React app? React › Testing | React | Testing | Beginner |
| 33 | 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 |
| 34 | What is the container and presentational component pattern in React? React › Design Patterns in React | React | Design Patterns in React | Intermediate |
| 35 | How do you clean up an effect in React, and why is it important? React › Effects & Lifecycle | React | Effects & Lifecycle | Intermediate |
| 36 | What is a higher order component in React? React › Higher-Order Components (HOCs) | React | Higher-Order Components (HOCs) | Intermediate |
| 37 | How would you use a higher order component to add authentication protection to a page? React › Higher-Order Components (HOCs) | React | Higher-Order Components (HOCs) | Intermediate |
| 38 | How would you use a ref to keep track of a component's previous prop value? React › Refs, useRef & forwardRef | React | Refs, useRef & forwardRef | Intermediate |
| 39 | What is the render props pattern in React? React › Render Props Pattern | React | Render Props Pattern | Intermediate |
| 40 | What is a common naming alternative to render props, using children as a function instead? React › Render Props Pattern | React | Render Props Pattern | Intermediate |
| 41 | What is a downside of the render props pattern that developers should be aware of? React › Render Props Pattern | React | Render Props Pattern | Intermediate |
| 42 | 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 |
| 43 | Why does Strict Mode call component functions and certain effects twice during development? React › Strict Mode & Concurrent Features | React | Strict Mode & Concurrent Features | Intermediate |
| 44 | How do you properly type the useState hook in a React component using TypeScript? React › TypeScript with React | React | TypeScript with React | Intermediate |
| 45 | Why is it important to unsubscribe from an RxJS observable, and what are common ways to do this correctly in Angular? Angular › RxJS & Observables | Angular | RxJS & Observables | Intermediate |
| 46 | How would you build a reusable error boundary that lets the user retry after an error occurs? React › Error Boundaries | React | Error Boundaries | Advanced |
| 47 | 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 |
| 48 | How would you use the React Profiler to find which components are causing performance problems? React › Performance (memo/useMemo) | React | Performance (memo/useMemo) | Advanced |
| 49 | How would you protect certain routes so only logged in users can access them? React › Routing | React | Routing | Advanced |
| 50 | How does the useFormStatus hook help show loading feedback while a server action is running? React › Server Actions & Data Mutations | React | Server Actions & Data Mutations | Advanced |