Yash Singh’s Post

Most React devs bring their SPA habits into Next.js — and their users pay the price. 👇 You've written it a hundred times: useState for data, useEffect to fetch it, a spinner while they wait. It works in React. In Next.js App Router, it's the wrong pattern entirely. Server Components let you fetch data inside the component — on the server, before the page hits the browser. No loading state. No extra JS bundle. No hydration issues. HTML that arrives ready. I've swapped dozens of useEffect fetch patterns for async Server Components and the Lighthouse scores jump immediately. Use the server for reads. Use useEffect for things only the browser can do. #NextJS #ReactJS #WebDevelopment #JavaScript #TypeScript #AppRouter #ServerComponents #ReactHooks #FrontendDeveloper #SoftwareEngineer #CleanCode #100DaysOfCode #WebPerformance #Programming #WebDev #NextJS14 #FullStackDeveloper #CodeQuality

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

Ever wondered what actually happens inside React when your app updates? React does not directly change the browser UI every time something updates. Instead, it creates a Virtual DOM, which is a lightweight copy of the real DOM. When data changes, React builds a new Virtual DOM and compares it with the previous version. This process is known as reconciliation. • React checks what has changed between two versions • It updates only those specific parts in the real DOM • This makes updates faster and avoids unnecessary reloading React also follows a component-based structure. Each component manages its own state and logic, making the code easier to understand, reuse, and maintain. When state or props change, React decides when and how to re-render efficiently. This is why React applications stay fast even when they become large and complex. For more details, go to the link and see the full post: https://lnkd.in/eU-YtJw7 #React #ReactJS #JavaScript #FrontendDevelopment #WebDevelopment #Programming #SoftwareEngineering #MERNStack

Day 14 - React.memo (Stop Unnecessary Re-renders) One of the biggest reasons React apps become slow is something most developers ignore: Unnecessary re-renders. Even when nothing changes, components keep re-rendering and that directly affects performance. That’s where React.memo helps. What React.memo does: • Prevents re-rendering when props don’t change • Improves performance in large applications • Helps optimize expensive components • Works using shallow comparison of props Simple idea: Without React.memo → Component re-renders every time parent renders With React.memo → Component re-renders only when props change When should you use it? • Large components • Lists with many items • Performance-critical UI parts • Components with expensive calculations Important note: Don’t use React.memo everywhere. Unnecessary memoization can actually hurt performance. Key takeaway: Optimization is not about using every tool it’s about using the right tool at the right place. Next, we’ll dive into useMemo and useCallback and how they help in real-world optimization. #Day14 #ReactJS #Performance #WebDevelopment #Frontend #JavaScript #Developers #Coding #LearningInPublic

Every time I start a new React project, I copy the same 5 hooks. Not from a library. From my own collection, battle-tested across 15+ production apps. These aren't clever abstractions. They're boring, reliable utilities that eliminate the same bugs I've fixed dozens of times: 1. useDebounce — stop hammering your API on every keystroke 2. usePrevious — track previous values without infinite re-render loops 3. useLocalStorage — state that survives refresh (SSR-safe, GDPR-aware) 4. useMediaQuery — responsive logic, not just responsive styles 5. useAbortController — cancel requests on unmount, prevent race conditions 5 files. ~150 lines total. Zero dependencies. Senior engineers don't write more code. They carry better defaults. Full TypeScript implementations you can copy today: https://lnkd.in/dguYtize What's the one custom hook you can't live without? #React #TypeScript #CustomHooks #WebDevelopment #JavaScript #DeveloperProductivity #CleanArchitecture #NodeJS

Good list - this is basically the 'React starter pack' ))) I’d add one more that saved me a lot of headaches - useAsync (or useRequest) - wraps loading/error/data + cancellation in one place. Especially useful when combined with AbortController to avoid race conditions and stale state updates.

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 🤩

Hot take: most React apps are over-engineered. After 7 years and hundreds of codebases, here's what I see teams reach for vs what they actually needed: ❌ Redux → ✅ Zustand ❌ Custom fetch everywhere → ✅ React Query ❌ Design system from scratch → ✅ Shadcn + Tailwind ❌ pages/components/hooks/utils folders → ✅ Feature-based folders Simple is not lazy. Simple is a decision. Match your tool to your problem — not to what the last senior dev you admired was using. Which one do you still see in production in 2026? 👇 #ReactJS #Frontend #JavaScript #FrontendEngineering #TypeScript #WebDevelopment #SoftwareEngineering

Your React app works. But is it fast? ⚡ Here are 11 performance tips every React dev should know: 1️⃣ React.memo → prevent unnecessary re-renders 2️⃣ useMemo → cache expensive calculations 3️⃣ useCallback → stable function references 4️⃣ Lazy load components → smaller initial bundle 5️⃣ Virtualize long lists → use react-window 6️⃣ Keep state local → don't over-use Redux/Context 7️⃣ Cache API responses → use React Query or SWR 8️⃣ Optimize images → WebP + loading="lazy" 9️⃣ Avoid layout thrashing → batch DOM reads & writes 🔟 No inline objects in JSX → define styles outside render 1️⃣1️⃣ Code split → dynamic imports for heavy components The golden rule? Profile first with React DevTools. Then optimize where it actually matters. Premature optimization is still a trap. 😅 Which of these do you already use? Drop it below 👇 #ReactJS #JavaScript #Frontend #WebPerformance #TechTips #WebDevelopment #FullStack