1. What is React Concurrent Rendering?

  2. How does React prioritize updates in concurrent mode?

  3. What is time slicing in React?

  4. What is the difference between async rendering and synchronous rendering?

  5. What is React Fiber architecture?

  6. How does the diffing algorithm work in React?

  7. What rules are covered by the diffing algorithm?

  8. What are the performance trade-offs of the Virtual DOM?

  9. How does React batch updates?

  10. What is selective hydration?

  11. How does React handle long-running tasks without blocking the UI?

  12. What is server streaming in React?

  13. What is React Server Components?

  14. What are the differences between CSR, SSR, and SSG?

  15. How does React handle hydration mismatches?

  16. What is React suspense for data fetching?

  17. What are render waterfalls and how do you avoid them?

  18. How do you optimize large React applications?

  19. What are common performance bottlenecks in React apps?

  20. How do you debug performance issues in React?

  21. What is memoization vs caching in React?

  22. How do you prevent unnecessary context re-renders?

  23. What are the pitfalls of using Context for global state?

  24. What is state normalization?

  25. What is the difference between Redux and Context API?

  26. When should Redux be preferred over Context?

  27. What is Redux Toolkit?

  28. What is Redux Thunk?

  29. What is Redux Saga?

  30. What is the difference between Redux Saga and Redux Thunk?

  31. What are selectors and why are they important?

  32. What is Reselect?

  33. What is Flux architecture?

  34. What is the mental model of Redux?

  35. What is the difference between Redux and MobX?

  36. What is optimistic UI updating?

  37. What is stale-while-revalidate pattern?

  38. What is React Query / TanStack Query?

  39. What is SWR?

  40. What is server state management?

  41. How do you handle cache invalidation in React apps?

  42. What are race conditions in React data fetching?

  43. What is request deduplication?

  44. What is React Router v6 architecture?

  45. How do you implement route guards in React Router?

  46. How do you manage 404 and fallback routes?

  47. What is code splitting by route?

  48. What are dynamic imports?

  49. What is tree shaking?

  50. What is bundle splitting strategy?

  51. What are micro-frontends?

  52. How does React support micro-frontends?

  53. What are web components and how do you integrate them with React?

  54. What is forward compatibility in React?

  55. What is backward compatibility in React?

  56. What are breaking changes in React upgrades and how do you handle them?

  57. What is React Strict Mode double rendering and why does it happen?

  58. What is hydration error and how do you fix it?

  59. What is controlled rehydration?

  60. What is render hijacking?

  61. What are higher-order components (HOCs) and their drawbacks?

  62. What are render props and their drawbacks?

  63. What are compound components?

  64. What is the compound component pattern?

  65. What is the container-presentational pattern?

  66. What is inversion of control in React?

  67. What is dependency inversion in component design?

  68. What are React anti-patterns in large-scale apps?

  69. What is the difference between React.memo and useMemo?

  70. What are the differences between useCallback and useMemo?

  71. What is useId and when should it be used?

  72. What is useTransition?

  73. What is useDeferredValue?

  74. What is useImperativeHandle?

  75. What is React Profiler?

  76. How do you measure component render performance?

  77. What is render phase vs commit phase?

  78. What is React reconciliation vs rendering?

  79. What is shadow DOM vs virtual DOM?

  80. How does React integrate with Web Workers?

  81. How do you handle memory leaks in React apps?

  82. What are stale closures in React hooks?

  83. What is dependency array bug and how do you avoid it?

  84. How do you test React components?

  85. What is Jest?

  86. What is React Testing Library?

  87. What is shallow rendering?

  88. What is snapshot testing?

  89. How do you test hooks?

  90. How do you test async behavior in React?

  91. What is mock server testing?

  92. What is contract testing in frontend?

  93. What is end-to-end testing in React apps?

  94. How do you implement feature flags in React?

  95. What is environment-based configuration in React?

  96. What is build-time vs runtime configuration?

  97. What is tree-shakeable code?

  98. What is bundle analysis and how do you perform it?

  99. How do you secure React applications?

  100. How does JSX prevent injection attacks?