CORS Explained Simply — Why Your Fetch Works in Postman but Fails in the Browser
Cross-Origin Resource Sharing in plain language: what blocks your request, what preflight means, and how to fix the errors you'll see in every frontend job.
6 min read3
Cross-Origin Resource Sharing in plain language: what blocks your request, what preflight means, and how to fix the errors you'll see in every frontend job.
Two patterns for taming fast events: debounce waits for silence, throttle limits how often. With examples, code, and interview answers.
Why your effect reads old state, fires twice, or loops forever — and the simple rules to fix it (interview-ready).
Three React APIs that all say 'memoize' — but they do different things. Clear explanations, examples, and a cheatsheet.
A CDN speeds up your app by serving assets from servers close to your users. Here's how it works and how Next.js takes advantage of it.
A practical guide to TypeScript enums, their runtime cost, and better alternatives for modern frontend apps.
Understand 'use client' in Next.js App Router: what it means, when to use it, and how it works under the hood.
Understand the key differences between the old Page Router and the new App Router in Next.js.
Understand Higher-Order Components (HOCs) in React with examples, use cases, downsides, and a comparison to hooks.
Event loop explained with a clean SVG timeline showing the actual execution order: Start → End → Promise → Timeout.
A simple guide to understanding when to use useRef and useState in React, with examples, mental models, and a quick cheatsheet.
A concise, example‑driven overview of the most useful frontend patterns for modern React/Next.js apps.
Clear, practical explanations of MVVM, micro‑frontends, and domain‑driven design for modern React/Next.js teams, with examples, folder structures, and trade‑offs.