Welcome to React Interview Prep

This course covers the React concepts interviewers actually probe on: the virtual DOM and reconciliation, props and state, the full hooks lineup, the render pipeline, events and forms, state management options, routing, performance, classic patterns, and testing.

What You'll Learn

• React Core Concepts - Library vs framework, virtual DOM and reconciliation, JSX vs HTML, component types and composition
• State and Props - Props down, state local, lifting state, controlled vs uncontrolled, immutability
• Hooks - useState, useEffect, useRef, useMemo/useCallback, useContext, useReducer, custom hooks
• Lifecycle and Rendering - Component lifecycle with hooks, re-rendering rules, React.memo, batching and concurrent React
• Events and Forms - Synthetic events, form handling patterns, debounced inputs and search
• State Management - When you need it, Context + reducer, Redux Toolkit, Zustand and Jotai
• React Router - Client-side routing, dynamic routes and navigation, protected routes
• Performance Optimization - Profiling, list virtualization, code splitting and lazy loading, image and asset optimization
• Patterns and Best Practices - HOCs, render props, compound components, error boundaries
• Testing and Interview Scenarios - Component testing, hooks and async testing, common coding challenges, interview question bank

How to Use This Course

Read the chapters in order - hooks and rendering build on the core concepts in Chapter 1. After each lesson, close the file and re-explain the concept out loud. Chapter 10's last lesson is the interview question bank - save it for the end as a self-test.

Prerequisites

• Working JavaScript knowledge (covered in the JS course)
• Comfort with HTML and CSS basics
• Node.js 20+ installed locally for running examples

Let's start with what React actually is.