100 Must-Know Redux Interview Questions and Answers 2025

Redux Fundamentals

1.
What is Redux and how is it used in web development?
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2.
Can you describe the three principles that Redux is based upon?
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3.
What is an action in Redux?
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4.
How are actions used to change the state in a Redux application?
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5.
What is a reducer in Redux and what role does it play?
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6.
How does Redux differ from local component state in React?
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7.
Define “store” in the context of Redux.
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8.
Can you describe the concept of “single source of truth” in Redux?
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9.
How do you create a Redux store?
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10.
What is meant by “immutable state,” and why is it important in Redux?
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11.
Explain the significance of the combineReducers function.
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12.
What are pure functions and side effects in the context of Redux?
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Redux Core Concepts

13.
How do you handle asynchronous actions in Redux?
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14.
What is a “selector” in Redux and what is its purpose?
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15.
How does Redux handle the flow of data and actions?
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16.
Can you explain the difference between a Container and Presentational component in Redux?
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17.
What is middleware in Redux and when would you use it?
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18.
How do you access the Redux store in a React component?
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19.
What is the purpose of the dispatch function in Redux?
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20.
What arguments does createStore receive in Redux?
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21.
Describe the subscribe function in Redux.
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Working with Redux Actions

22.
How do you structure action creators in Redux?
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23.
What is an action type and how is it used in Redux?
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24.
Can you give an example of a synchronous action creator?
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25.
How do you handle complex state logic in actions?
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26.
Explain the concept of action creators returning a function for asynchronous operations.
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Reducers and State Management

27.
How do reducers handle state changes in response to different action types?
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28.
What is meant by a “slice reducer”?
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29.
Describe how to properly update the state based on an action.
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30.
How would you reset the state of a Redux store?
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31.
Can you discuss reducer composition and its benefits?
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32.
What is the significance of immutability in reducer functions?
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33.
How do you handle initial state in Redux reducers?
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34.
What are common pitfalls when writing reducers?
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Redux Middleware and Side Effects

35.
What is redux-thunk and how does it work?
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36.
Can you explain the purpose of redux-saga and how it compares to redux-thunk?
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37.
What is a “side effect” and how do middlewares handle them in Redux?
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38.
How do you write a custom middleware for Redux?
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39.
Discuss how middlewares can enhance the capabilities of a Redux store.
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Redux and UI Integration

40.
How do you connect a React component to a Redux store?
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41.
What are the advantages of using React-Redux’s connect function?
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42.
Can you describe the mapStateToProps and mapDispatchToProps functions?
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43.
Explain the Provider component from React-Redux.
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44.
How do you use hooks like useDispatch and useSelector in React functional components?
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45.
What performance considerations should be taken into account when connecting components to Redux?
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46.
How can you optimize the performance of Redux-connected components?
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Advanced Redux Patterns

47.
What are Higher Order Reducers (HORs) and how are they used?
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48.
Can you implement a feature toggle mechanism using Redux?
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49.
How do you normalize a state shape in Redux?
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50.
What is a Redux “slice” and how is it used?
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51.
Explain the “Ducks” pattern in Redux.
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Redux State Normalization

52.
Why is state normalization recommended in Redux?
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53.
How do you structure a normalized state?
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54.
What are the benefits of state denormalization?
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55.
Can you explain how to manage entity relations in a normalized Redux state?
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Redux Ecosystem and Utilities

56.
What is Immutable.js and how can it be used with Redux?
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57.
Discuss the Redux DevTools extension and its features.
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58.
How do reselect and memoized selectors work in Redux?
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59.
What are common utilities and libraries used in conjunction with Redux?
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60.
Describe the significance of the Redux Toolkit and how it helps Redux development.
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Testing Redux Applications

61.
How do you test Redux reducers?
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62.
What is the recommended approach to test Redux actions?
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63.
How can you test a Redux-connected React component?
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64.
Describe the process of testing asynchronous action creators.
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65.
What tools can you use to facilitate testing in Redux applications?
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Redux with Other Frameworks and Libraries

66.
How do you integrate Redux with a framework other than React, like Angular or Vue?
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67.
Can Redux be used with server-side rendering frameworks like Next.js?
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68.
Discuss the use of Redux with React Native.
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69.
What adaptations are needed to use Redux outside of a UI environment (e.g., in a Node.js backend)?
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Scaling Redux for Large Applications

70.
How do you organize your files and folders in a large Redux application?
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71.
What strategies can be used to scale Redux actions and reducers?
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72.
Can you explain the concept of “domain-driven design” in the context of a Redux state tree?
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73.
How do feature modules and code splitting affect Redux state management?
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74.
Discuss strategies for managing complex application state with Redux.
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Redux Performance Optimization

75.
How do you prevent unnecessary renders in Redux-connected components?
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76.
What techniques are available to reduce the size of the Redux store?
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77.
How do you optimize Redux action dispatch and payload size?
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78.
What are best practices for ensuring a scalable Redux state management with large datasets or frequent updates?
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Redux and Forms

79.
How do you manage form state with Redux?
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80.
Discuss the use of libraries like Redux Form or React Final Form with Redux.
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81.
What are the trade-offs of keeping form state in the Redux store?
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Redux and Authentication

82.
How do you manage user authentication and session state in Redux?
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83.
What considerations should be made for security when storing tokens or sensitive information in Redux?
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84.
How do you manage login and logout workflows with Redux actions and reducers?
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Migrating to Redux and State Hydration

85.
How do you approach migrating a legacy application state management to Redux?
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86.
Can you explain the concept of “state hydration” in the context of SSR and Redux?
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87.
What challenges might arise when integrating Redux into an existing application and how would you address them?
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Redux Future and Community

88.
Describe the current trends and community practices around Redux.
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89.
How has Redux evolved to fit into the modern React ecosystem with hooks?
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90.
What do you believe is the future of Redux given the context of emerging state management libraries?
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Advanced State Modeling in Redux

91.
How do you model complex state dependencies and computations in Redux?
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92.
Discuss your approach to type checking and ensuring state consistency.
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93.
How do you tackle transactional updates in Redux?
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94.
What strategies would you use for undo/redo functionality in a Redux application?
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Redux Interoperability

95.
How does Redux interact with WebSockets or external data sources?
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96.
Discuss the integration of GraphQL in a Redux-managed application.
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97.
How would you manage local vs. server state in a Redux application?
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Redux API Requests and Caching

98.
How do you structure API requests in Redux actions?
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99.
Discuss methods for caching API responses in the Redux store.
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100.
What patterns or libraries do you use to manage RESTful or GraphQL API interactions with Redux?
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100 Redux interview questions

What is Redux and how is it used in web development?

Can you describe the three principles that Redux is based upon?

What is an action in Redux?

How are actions used to change the state in a Redux application?

What is a reducer in Redux and what role does it play?

How does Redux differ from local component state in React?

Define “store” in the context of Redux.

Can you describe the concept of “single source of truth” in Redux?

How do you create a Redux store?

What is meant by “immutable state,” and why is it important in Redux?

Explain the significance of the combineReducers function.

What are pure functions and side effects in the context of Redux?

How do you handle asynchronous actions in Redux?

What is a “selector” in Redux and what is its purpose?

How does Redux handle the flow of data and actions?

Can you explain the difference between a Container and Presentational component in Redux?

What is middleware in Redux and when would you use it?

How do you access the Redux store in a React component?

What is the purpose of the dispatch function in Redux?

What arguments does createStore receive in Redux?

Describe the subscribe function in Redux.

How do you structure action creators in Redux?

What is an action type and how is it used in Redux?

Can you give an example of a synchronous action creator?

How do you handle complex state logic in actions?

Explain the concept of action creators returning a function for asynchronous operations.

How do reducers handle state changes in response to different action types?

What is meant by a “slice reducer”?

Describe how to properly update the state based on an action.

How would you reset the state of a Redux store?

Can you discuss reducer composition and its benefits?

What is the significance of immutability in reducer functions?

How do you handle initial state in Redux reducers?

What are common pitfalls when writing reducers?

What is redux-thunk and how does it work?

Can you explain the purpose of redux-saga and how it compares to redux-thunk?

What is a “side effect” and how do middlewares handle them in Redux?

How do you write a custom middleware for Redux?

Discuss how middlewares can enhance the capabilities of a Redux store.

How do you connect a React component to a Redux store?

What are the advantages of using React-Redux’s connect function?

Can you describe the mapStateToProps and mapDispatchToProps functions?

Explain the Provider component from React-Redux.

How do you use hooks like useDispatch and useSelector in React functional components?

What performance considerations should be taken into account when connecting components to Redux?

How can you optimize the performance of Redux-connected components?

What are Higher Order Reducers (HORs) and how are they used?

Can you implement a feature toggle mechanism using Redux?

How do you normalize a state shape in Redux?

What is a Redux “slice” and how is it used?

Explain the “Ducks” pattern in Redux.

Why is state normalization recommended in Redux?

How do you structure a normalized state?

What are the benefits of state denormalization?

Can you explain how to manage entity relations in a normalized Redux state?

What is Immutable.js and how can it be used with Redux?

Discuss the Redux DevTools extension and its features.

How do reselect and memoized selectors work in Redux?

What are common utilities and libraries used in conjunction with Redux?

Describe the significance of the Redux Toolkit and how it helps Redux development.

How do you test Redux reducers?

What is the recommended approach to test Redux actions?

How can you test a Redux-connected React component?

Describe the process of testing asynchronous action creators.

What tools can you use to facilitate testing in Redux applications?

How do you integrate Redux with a framework other than React, like Angular or Vue?

Can Redux be used with server-side rendering frameworks like Next.js?

Discuss the use of Redux with React Native.

What adaptations are needed to use Redux outside of a UI environment (e.g., in a Node.js backend)?

How do you organize your files and folders in a large Redux application?

What strategies can be used to scale Redux actions and reducers?

Can you explain the concept of “domain-driven design” in the context of a Redux state tree?

How do feature modules and code splitting affect Redux state management?

Discuss strategies for managing complex application state with Redux.

How do you prevent unnecessary renders in Redux-connected components?

What techniques are available to reduce the size of the Redux store?

How do you optimize Redux action dispatch and payload size?

Explain the significance of the `combineReducers` function.

What is the purpose of the `dispatch` function in Redux?

What arguments does `createStore` receive in Redux?

Describe the `subscribe` function in Redux.

What is `redux-thunk` and how does it work?

Can you explain the purpose of `redux-saga` and how it compares to `redux-thunk`?

What are the advantages of using React-Redux’s `connect` function?

Can you describe the `mapStateToProps` and `mapDispatchToProps` functions?

Explain the `Provider` component from React-Redux.

How do you use hooks like `useDispatch` and `useSelector` in React functional components?

How do `reselect` and memoized selectors work in Redux?