How React works under the Hood | React reconciliation, fibre , diffing , key| ReactJS Full Course #6

Description

How React Works Under the Hood | React Reconciliation, Fiber, Diffing & Keys Explained Ever wondered how React updates your UI so fast? What's happening behind the scenes when you click a button or change state? In this video, I break down React's internal architecture from first principles - no hand-waving, no buzzwords, just pure engineering concepts. **What You'll Learn:** 🔹 **Virtual DOM & React Elements** - What they actually are (not what tutorials claim) 🔹 **Reconciliation Algorithm** - How React finds differences between old and new UI in O(n) time instead of O(n³) 🔹 **React Fiber Architecture** - The secret data structure that replaced recursion with a linked list 🔹 **Diffing Algorithm** - The two brutal trade-offs React makes to stay blazingly fast 🔹 **Keys in Lists** - Why they're not just about warnings, but about performance and correctness 🔹 **Double Buffering** - How React maintains two trees and swaps them instantly 🔹 **Interruptible Rendering** - How Fiber enables React to pause, prioritize, and resume work **Why This Matters:** Understanding these concepts will make you write better React code. You'll know: - When to use React.memo and when it's useless - Why keys matter beyond silencing warnings - How to structure components for optimal performance - What actually causes re-renders (and what doesn't) This isn't just theory - this knowledge has helped me optimize production apps used by millions of users. **Perfect for:** - React developers who want to level up - Anyone preparing for senior React interviews - Developers tired of cargo-cult programming - Engineers who learn by understanding "why" not just "how" If you believe in first-principles learning like I do, this video is for you. 🔔 Subscribe for more deep-dives into React, JavaScript, and Web Performance 💬 Drop your questions in the comments - I read and respond to all of them **Follow Coder Army:** 🐦 Twitter: [Your Twitter] 📷 Instagram: [Your Instagram] 💼 LinkedIn: [Your LinkedIn] #React #ReactJS #WebDevelopment #JavaScript #ReactFiber #Programming #CodingTutorial #WebDev #ReactReconciliation #CoderArmy --- Visit Strike: https://strikes.in/ Class start from 1 december Visit Coder Army Website: https://coderarmy.in/#home Course start date: 1 september Timing: 6pm (Mon-fri) Hackathon will be organised after course completion Join Premium Whatsapp Group: https://whatsapp.com/channel/0029Va6H0tbHVvTbcuT99Y1f Class Notes :https://www.notion.so/Lecture06-React-Virtual-DOM-Reconciliation-Complete-Study-Notes-2c43a78e0e228052ad82e4899bf42cb4?source=copy_link Code Link: https://github.com/coderarmy-notes/mern-stack-course Twitter: https://x.com/rohit_negi9?s=21 Channel: ‪@CoderArmy9‬ Buy Our Premium Course of Web dev+Blockchain+HLD+DSA: https://rohittnegi.akamai.net.in/new-courses/4-web-development-block-chain (5500 only) Time Stamp: #javascript #webdevelopment #mernstack