React Key Mistakes: Avoid Using Index as Key

Your React app is slow. Here's why. 🐢 Most devs jump straight to optimization tools. But 90% of the time, the fix is simpler: 🔴 Fetching data in every component independently → Lift it up or use a global state solution 🔴 Importing entire libraries for one function → `import _ from 'lodash'` hurts. Use named imports. 🔴 No lazy loading on heavy routes → React.lazy() exists. Use it. 🔴 Images with no defined size → Layout shifts kill perceived performance 🔴 Everything in one giant component → Split it. React re-renders what changed, not what didn't. Performance isn't magic. It's just not making avoidable mistakes. Save this for your next code review. 🔖 #ReactJS #Frontend #WebPerformance #JavaScript #WebDev

This small React mistake can break your entire app 👇 Many developers write code like this: if (condition) return null; useEffect(() => { // logic }, []); Looks fine, right? ❌ But it can cause a serious error. 💥 Error: "Rendered fewer hooks than expected" 🔍 Why this happens React has a strict rule: 👉 Hooks must be called in the same order on every render 📌 What actually happens: • 1st render → early return → useEffect NOT called • 2nd render → useEffect called 👉 Hook order mismatch = 💣 error ✅ Fix Always call hooks first, then apply conditions: useEffect(() => { // logic }, []); if (condition) return null; 💡 Rule to remember: Never call hooks conditionally. Keep them at the top level. Have you ever faced this error before? 👇 #react #nextjs #javascript #webdevelopment #frontend

I think this is a common mistake among beginners. If you're a beginner and want to avoid this, it's better to use ESLint or Biome. I recommend using Biome it's faster, and the default settings are actually pretty good 🤩

Most React apps I inherit are shipping 2–3x more JavaScript than they need to. Not because the developers were careless. Because the defaults only take you so far. Vite and Webpack do a lot automatically but "automatic" breaks down fast once a codebase grows past one person. Imports pile up. Lazy loading never gets added. Third-party libraries get pulled in whole when you needed one function. Two things I almost always find misconfigured: ↳ Tree Shaking — not broken, just quietly undermined One CommonJS module, one barrel file exporting everything, one dynamic require() and the bundler can't eliminate unused code anymore. It silently includes it all. I've opened bundles where a date formatting library takes up more space than the entire app logic. ↳ Code Splitting — set up once, never revisited The initial route split exists. But the dashboard, the settings panel, the admin section, they're all loading on page one for users who will never see them. That's real kilobytes hitting real users on real 4G connections. On a recent e-commerce project, fixing both dropped the initial JS payload from 680kb to 290kb. The client saw a measurable drop in bounce rate on mobile within two weeks. If you're running a web product and haven't looked at your bundle in a while, there's almost certainly weight in there that shouldn't be. I do a free bundle audit for new clients. I'll pull up your build output, identify exactly what's bloating it, and give you a prioritized fix list. No vague recommendations. DM me if you want one.

Most developers try to optimize React apps… without knowing what’s actually slow. That’s the problem. Before you optimize… You need to measure. That’s where the React Profiler comes in 🔍 ⚡ What is React Profiler? A tool (inside React DevTools) that shows: • Which components are re-rendering • How long each render takes • Why a component re-rendered 🧠 What it helps you discover • Unnecessary re-renders • Slow components • Expensive computations • Props/state changes causing re-renders 🔍 Real example You click a button and suddenly the whole page re-renders. Profiler shows: 👉 A parent component updated 👉 All child components re-rendered 👉 Even the ones that didn’t need to 🚀 How to fix (after profiling) • Wrap components with React.memo • Use useMemo for heavy calculations • Use useCallback for stable functions • Avoid passing new object/array references 💡 Biggest mistake Optimizing blindly. Adding memoization everywhere… without knowing if it even helps. Measure → Identify → Optimize That’s the correct flow. 💡 React performance is not about writing more code. It’s about writing smarter code based on data. Have you ever used React Profiler to fix a real issue? 👇 #React #Frontend #WebPerformance #JavaScript #SoftwareEngineering #WebDevelopment

Day 22: Error Boundaries in React In real-world applications, errors can happen anytime. A single error in one component can crash the entire UI. To handle this properly, React provides: Error Boundaries 📌 What are Error Boundaries? Error Boundaries are React components that catch JavaScript errors in their child component tree and display a fallback UI instead of crashing the whole app. ✅ Prevents complete app crash ✅ Displays fallback UI ✅ Improves user experience 📌 What Error Boundaries can catch? ✔ Errors in rendering ✔ Errors in lifecycle methods ✔ Errors in constructors of child components 📌 What Error Boundaries cannot catch? ❌ Errors inside event handlers ❌ Errors in async code (setTimeout, promises) ❌ Errors in server-side rendering 📌 Example of an Error Boundary import React from "react"; class ErrorBoundary extends React.Component { constructor(props) { super(props); this.state = { hasError: false }; } static getDerivedStateFromError(error) { return { hasError: true }; } componentDidCatch(error, info) { console.log("Error:", error); console.log("Info:", info); } render() { if (this.state.hasError) { return <h2>Something went wrong!</h2>; } return this.props.children; } } export default ErrorBoundary; 📌 How to use it? import ErrorBoundary from "./ErrorBoundary"; import App from "./App"; function Main() { return ( <ErrorBoundary> <App /> </ErrorBoundary> ); } Now, if any child component crashes, the app will show: 👉 "Something went wrong!" 📌 Why Error Boundaries are important? 🔥 Used in production apps 🔥 Prevents blank screens 🔥 Helps debugging errors #ReactJS #ErrorBoundary #FrontendDevelopment #JavaScript #WebDevelopment #CodingJourney #LearnInPublic

🚨 𝗧𝗵𝗶𝘀 𝘀𝗺𝗮𝗹𝗹 ! 𝗶𝗻 𝗧𝘆𝗽𝗲𝗦𝗰𝗿𝗶𝗽𝘁 𝗰𝗮𝗻 𝗰𝗿𝗮𝘀𝗵 𝘆𝗼𝘂𝗿 𝗲𝗻𝘁𝗶𝗿𝗲 𝗮𝗽𝗽. 𝗬𝗲𝘀… 𝘀𝗲𝗿𝗶𝗼𝘂𝘀𝗹𝘆. I once saw code like this: user!.name At first glance, it looks harmless. But this one symbol can silently introduce runtime bugs if you don’t understand it. 💡 𝗦𝗼 𝘄𝗵𝗮𝘁 𝗱𝗼𝗲𝘀 ! 𝗮𝗰𝘁𝘂𝗮𝗹𝗹𝘆 𝗱𝗼? It’s called the 𝗡𝗼𝗻-𝗡𝘂𝗹𝗹 𝗔𝘀𝘀𝗲𝗿𝘁𝗶𝗼𝗻 𝗢𝗽𝗲𝗿𝗮𝘁𝗼𝗿 👉 It tells TypeScript: “Trust me, this value is NOT null or undefined.” 🔍 𝗘𝘅𝗮𝗺𝗽𝗹𝗲: const name: string | undefined = undefined; name!.toUpperCase(); 💥 𝗕𝗼𝗼𝗺. 𝗖𝗿𝗮𝘀𝗵. 👉 TypeScript stays quiet 👉 JavaScript throws the error Because YOU told TypeScript: “Trust me” …and it did 😅 🧠 𝗧𝗵𝗲 𝗿𝗲𝗮𝗹 𝗽𝗿𝗼𝗯𝗹𝗲𝗺? ! doesn’t make your code safe It just 𝗵𝗶𝗱𝗲𝘀 𝘁𝗵𝗲 𝘄𝗮𝗿𝗻𝗶𝗻𝗴 🔥 𝗕𝗲𝘁𝘁𝗲𝗿 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵: if (name) { name.toUpperCase(); } ✔ Safe ✔ Predictable ✔ No surprises 👉 If you’re using !, ask yourself: “Am I 100% sure this will never be null?” If not… don’t use it. 💬 𝗛𝗮𝘃𝗲 𝘆𝗼𝘂 𝗲𝘃𝗲𝗿 𝗳𝗮𝗰𝗲𝗱 𝗮 𝗯𝘂𝗴 𝗯𝗲𝗰𝗮𝘂𝘀𝗲 𝗼𝗳 !? #TypeScript #ReactJS #Frontend #WebDevelopment #JavaScript #CodingTips #SoftwareEngineering

🔴90% of React applications have performance issues... and most developers don't even realize it. that might sound surprising but it's true. React is fast but it isn't automatically optimized. optimization is your responsibility. so what actually makes a React app slow? the reasons vary but the root cause is almost always the same: unnecessary re-renders. React's main task is to make sure your UI is up to date with your state and when your state changes, it should update the UI. That's normal, right? That's React doing its job. The problem is when it updates UI components that weren't even affected by the state change. think about it You have a parent component with state and inside it, there are 10 child components and only one of them was affected by your state change. But React? it re-renders all 10 of them that's exactly where performance dies. 📌So what actually solves this problem? 🔸React.Memo: it's like saying to React, "Hey, man, only update this component if its own props changed." 🔸useMemo: to remember results of heavy computations, so it doesn't compute it every time it renders۔ 🔸useCallback: to stop functions from being recreated, which would then make your child components re-render. but❗ and this is an important but don't use these tools blindly... first, use React DevTools Profiler to see if it's actually an issue۔ and then optimize۔ optimizing prematurely is like adding complexity without any real benefit. the secret to React performance is simple: move your state to the right place, and only update what needs updating🚀 how do you measure performance in your React applications? 👇 #ReactJS #WebDevelopment #MERNStack #JavaScript #Frontend #Performance #SoftwareEngineering #CodingTips #TechCommunity

What if you never had to build an API for your Laravel + Vue app? That's exactly what Inertia.js does. And in 2026, with v3 just released, it's better than ever. 🚀 Here's the idea: Instead of: Laravel API → CORS → token auth → Axios → state management → Vue You get: Laravel controller → Inertia → Vue component (as props) Your controllers return Inertia::render() instead of JSON. Vue components receive data as props. Laravel handles routing, auth, validation, and sessions — exactly as always. No duplication. No boilerplate. What Inertia v3 ships (March 2026): → No more Axios — built-in XHR client cuts ~15KB from your bundle → useHttp hook — reactive HTTP requests outside of page navigation (search, autocomplete) → Optimistic updates — instant UI changes with automatic rollback on error → SSR works in npm run dev — no more separate Node.js process during development → useLayoutProps — clean page-to-layout communication, no event bus needed And the features that were already amazing: ✔ useForm — Laravel validation errors mapped to fields automatically ✔ Shared data — auth user, flash messages available on every page ✔ Persistent layouts — sidebar never re-renders between navigations ✔ Inertia::optional() — lazy load expensive data only when needed I wrote the complete deep dive for installation to shared data, forms, persistent layouts, and when NOT to use Inertia. Are you already using Inertia.js? What stack are you pairing it with? #Laravel #InertiaJS #Vue #PHP #WebDevelopment #FullStack #100DaysOfBlogging

🚀 Understanding State Management in React / JavaScript State management is one of the most important concepts when building scalable frontend applications. As your app grows, managing data efficiently becomes critical. Here’s a simple breakdown of popular state management approaches: 🔹 React Context Best for small to medium apps. Built-in and easy to use, but can become hard to manage in large-scale applications. 🔹 Redux A powerful centralized store for managing global state. Great for large applications, but comes with more boilerplate. 🔹 Recoil Modern and flexible. Uses atoms and selectors, making state more modular and easier to manage. 🔹 Zustand Lightweight and simple. Minimal setup with great performance—perfect for fast development. 💡 Key takeaway: There’s no “one-size-fits-all” solution. Choose based on your project size, complexity, and team needs. If you're working with React or Next.js, mastering state management will level up your development skills significantly. #React #JavaScript #FrontendDevelopment #StateManagement #WebDevelopment #NextJS