JavaScript Web APIs Mastery Guide

This repository is a comprehensive learning resource for mastering JavaScript Web APIs, designed for senior frontend developers (SDE2/SDE3 level) preparing for technical interviews and high-scale production development.

🚀 Repository Structure

The content is organized into logical categories, each containing in-depth documentation, real-world examples, and interview preparation.

📁 common/

Core concepts that every senior developer must master:

• How Web APIs Work
• Browser Architecture
• Event Loop & Web APIs
• Security Considerations
• Performance Patterns

📁 http-and-network/

• Fetch API
• Axios vs Fetch
• AbortController
• WebSockets
• Server-Sent Events (SSE)

📁 storage/

• LocalStorage & SessionStorage
• Cookies
• IndexedDB
• Cache API

📁 observers/

• Intersection Observer
• Mutation Observer
• Resize Observer

📁 background-processing/

• Web Workers
• Service Workers (PWA)

📁 pwa/

• Service Workers (PWA 🔥)

📂 Comprehensive API List

javascript-web-apis/ 
  ├── fetch-api 
  ├── axios-vs-fetch 
  ├── abort-controller (cancel requests) 
  ├── localstorage-sessionstorage 
  ├── cookies 
  ├── indexeddb (advanced browser storage) 
  ├── cache-api (PWA caching) 
  ├── dom-events-basics 
  ├── dom-events-advanced 
  ├── event-delegation 
  ├── intersection-observer 
  ├── mutation-observer 
  ├── resize-observer 
  ├── geolocation-api 
  ├── clipboard-api 
  ├── notifications-api 
  ├── permissions-api 
  ├── fullscreen-api 
  ├── visibility-api (page visibility) 
  ├── web-workers 
  ├── service-workers (PWA 🔥) 
  ├── websockets 
  ├── server-sent-events (SSE) 
  ├── history-api 
  ├── url-api 
  ├── file-api (file upload/preview) 
  ├── drag-and-drop-api 
  ├── media-devices-api (camera/mic) 
  ├── speech-recognition-api 
  ├── web-audio-api 
  ├── web-animation-api 
  ├── performance-api 
  ├── timing-api (LCP, FCP basics)

🛠 Each API Folder Contains:

1. explanation.md: Deep dive into the API.
2. how-it-works.md: The technical "under the hood" mechanics.
3. when-to-use.md: Decision-making framework.
4. real-world-usecases.md: Practical applications in production.
5. edge-cases.md: Gotchas, browser quirks, and error handling.
6. performance.md: Optimization strategies.
7. security.md: Security best practices (XSS, CSRF, etc.).
8. examples/: Code snippets (basic, advanced, error-handling).
9. mini-project/: A hands-on implementation.
10. interview-questions.md: SDE2 level interview prep.

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Created for senior developers aiming for top-tier tech companies.