Arka S.’s Post

Your React App is Slow… and You Might Be the Reason Most developers use useMemo and React.memo but very few actually understand when NOT to use them ⚠️ I recently debugged a performance issue in a React dashboard. Everything looked optimized — but still, the UI was lagging. The reason? 👉 Memoization was used… but used wrongly. ⚡ Let’s break it down simply: 🔹 useMemo — Caches Calculations Use it when you have expensive computations Example: const filteredData = useMemo(() => { return data.filter(item => item.active); }, [data]); ✔ Prevents unnecessary recalculations ❌ Useless for cheap operations 🔹 React.memo — Stops Re-renders Wrap your component to avoid re-render when props don’t change const Card = React.memo(({ item }) => { return <div>{item.name}</div>; }); ✔ Great for large lists / heavy UI ❌ Useless if props change every render 🔥 The Real Problem Most people do this: Wrap everything in React.memo Add useMemo everywhere Hope performance improves 👉 Result: More complexity, same performance (sometimes worse) 💡 What Actually Works ✔ Use useMemo only for heavy calculations ✔ Use React.memo only when re-renders are costly ✔ Avoid passing new object/array references every render ✔ Measure performance before optimizing 🧠 The Mindset Shift Optimization is not about adding hooks It’s about removing unnecessary work 🚀 Final Takeaway Don’t optimize blindly. First understand: Why is it re-rendering? Is it actually slow? Then use the right tool. 👇 Curious — have you ever faced unnecessary re-renders in your app? #ReactJS #FrontendDevelopment #JavaScript #WebPerformance #ReactHooks #SoftwareEngineering #CleanCode #DevTips

🔗 When My App Finally Spoke — The Power of APIs & Backend Development I built the UI. I designed the components. Everything looked perfect… But it couldn’t remember anything. It couldn’t fetch real data. That’s when I realized, a frontend alone isn’t enough. In my latest Medium article, I share how learning APIs and backend development transformed my projects from static interfaces into real, connected applications that can store, communicate, and respond. This was the moment my app finally felt alive. 👉 Read the full article here: https://lnkd.in/gNT-WUXR Curious to know — when did your app first “come alive”? 💬 #WebDevelopment #APIs #BackendDevelopment #FullStackDevelopment #JavaScript #NodeJS #ReactJS #MERNStack #CodingJourney #LearningInPublic #TechGrowth #WomenInTech

Day [9] of learning Code for Change When I started learning Next.js, I thought loading states were just about showing a spinner. Turns out, it’s way more powerful than that. Here’s what I learned about loading.js in the App Router: → You can create a loading.js file inside a route folder → It automatically shows a fallback UI while the page is loading → No need to manually manage loading state with useState/useEffect That means cleaner code + better user experience. Example: If your folder looks like this: app/dashboard/page.js app/dashboard/loading.js Then Next.js will automatically show loading.js while page.js is fetching data. Why this is useful: Users don’t stare at a blank screen Your app feels faster (even if data takes time) Less boilerplate code Still exploring more about streaming and Suspense in Next.js that’s where things get really interesting #NextJS #WebDevelopment #Frontend #JavaScript #LearningInPublic

💥 Most developers assume using useMemo and useCallback everywhere will automatically make a React app faster. Sounds logical: Memoize more → fewer re-renders → better performance. But in real-world apps, it often doesn’t work like that. I’ve seen this pattern quite often — developers start adding these hooks with good intent, but without actually measuring anything. • Wrapping functions with useCallback • Memoizing even simple values • Adding optimizations “just in case” And then… 🚨 No real performance improvement 🚨 Code becomes harder to read and maintain 🚨 Debugging gets more complicated 🚨 Sometimes performance even degrades 🧠 The important part: useMemo and useCallback are not free. They introduce overhead — memory usage, dependency comparisons, and extra complexity. ⚡ What actually works better: • Understanding why components re-render • Improving state structure • Splitting components smartly • Measuring performance using React DevTools 🔥 My take: React is already quite fast. Blindly adding memoization often creates more problems than it solves. 💡 Rule I follow: If I haven’t measured a real performance issue, I don’t reach for useMemo or useCallback. Curious — do you think these hooks are overused in most React apps? 🤔 #ReactJS #FrontendDevelopment #WebPerformance #JavaScript #SoftwareEngineering #ReactPerformance

🚀 Stop re-rendering your entire React app — here's why it's hurting you. One of the most common mistakes I see in React codebases is placing state too high in the component tree. When state lives at the top, every tiny update triggers a cascade of re-renders — even for components that don't care about that change. Here's what I do instead: ✅ Co-locate state — keep state as close to where it's used as possible. ✅ Use React.memo wisely — memoize components that receive stable props. ✅ Split context — separate frequently changing data from static config. ✅ Reach for useMemo & useCallback — but only when profiling confirms it helps. The result? A snappier UI, cleaner architecture, and fewer mysterious bugs. The React team built these tools for a reason — it's just about knowing when and where to apply them. 💬 What's your go-to trick for keeping React apps performant? Drop it in the comments — I'd love to learn from you! #React #WebDevelopment #Frontend #JavaScript #SoftwareEngineering

⚠️ This AsyncStorage mistake can silently break your React Native app… Think you’re handling storage correctly? Try this 👇 👉 Which pattern is WRONG? A️ await AsyncStorage.setItem('user', JSON.stringify(user)); B️ const user = await AsyncStorage.getItem('user'); console.log(JSON.parse(user)); C️ AsyncStorage.setItem('token', token); D️ const data = AsyncStorage.getItem('key'); console.log(data); 💥 Correct Answer: D You’re logging a Promise, not the actual value. AsyncStorage is asynchronous. If you skip await, your data isn’t ready when you use it. 🧠 Fix: const data = await AsyncStorage.getItem('key'); 🚫 Common impact: • Random UI bugs • Data mismatch • Debugging nightmares 💬 Be honest — have you made this mistake before? 🔁 Follow for daily React Native insights that actually matter. #ReactNative #JavaScript #AsyncStorage #MobileDev #Debugging #Frontend #CodingMistakes #LearnToCode #DevTips

🎯 Have you ever felt your React app was re-rendering more than it should… and you didn’t realize it? Everything looked fine But under the hood → unnecessary UI updates were killing performance 😵💫 Then I learned this 👇 👉 React doesn’t care if your UI “looks same” 👉 If state/props change → it re-renders 💡 The real problem: Global state (like Context API) → triggers re-renders everywhere Components update even when their data didn’t change This is the core issue behind unnecessary UI updates 🧠 What helped me fix it: ⚡ Context Splitting → Break global state into smaller pieces 🎯 Selectors → Subscribe only to specific state (not entire context) 🧩 Memoization → Use React.memo, useMemo, useCallback to avoid useless recalculations 🔥 The mindset shift: 👉 “Not every re-render is bad… but unnecessary ones are expensive.” Since understanding this: My UI feels smoother Debugging became easier I started thinking like a performance-focused developer If you're working with React, this is something you can’t ignore. 💬 Have you ever faced unnecessary re-renders in your app? #ReactJS #FrontendDevelopment #WebPerformance #JavaScript #Coding

Nobody talks about this React performance trap — and it bit me hard in production. I was using useContext to manage auth + theme + cart state in a mid-size app. Only a few components actually used the cart state. But every time the cart updated — every single component consuming the context re-rendered. Even the ones that only needed the user's name. Here's why: React's Context API re-renders all consumers whenever the context value reference changes — regardless of which slice of state they actually use. There are workarounds with Context: → Split into multiple contexts (AuthContext, CartContext, ThemeContext separately) → Wrap consumers in React.memo() → Use useMemo to stabilize the context value But honestly? All of these feel like duct tape. This is exactly where Zustand and Redux Toolkit shine. Both let you subscribe to only the slice of state you need. A component using useSelector(state => state.user.name) will only re-render when that specific value changes — not when the cart updates, not when the theme toggles. ZUSTAND Minimal boilerplate, great for small-to-mid apps. Selector-based subscriptions built in. REDUX TOOLKIT Structured, scalable. useSelector memoizes out of the box with Reselect. The lesson I took away: useContext is great for low-frequency, global state (auth, theme, locale). The moment you have state that changes often and is consumed by many components — reach for a proper state manager. Performance issues in React are rarely obvious until they're in production. Knowing why re-renders happen matters more than memorizing which hook to use. Have you run into this? Would love to hear how you solved it — Context splitting, Zustand, RTK, or something else entirely? #ReactJS #JavaScript #WebDevelopment #Frontend #Zustand #Redux

I used to think if a Next.js app runs fine, then it’s fine. Pages load. API works. UI responds. But I have learned something that changed how I build everything An app can “work” and still be architecturally wrong. Not broken. Not failing. Just quietly inefficient. The kind of issues you don’t notice at first: pages shipping way more JavaScript than they should unnecessary client-side rendering everywhere data fetching patterns that slow the whole experience down And the frustrating part is… everything still looks correct. I have seen this in my own projects and in codebases from experienced devs. The real problem isn’t React or Next.js. It’s how easy it is to blur the line between client and server without realizing it. Next.js doesn’t just render UI it forces you to think differently: What should actually run on the server? What needs to be interactive on the client? What should be cached vs always fetched fresh? Where does data really belong? In plain React, you don’t even think about half of this. But in Next.js, those small decisions quietly define your entire architecture. And if you get them wrong, nothing breaks… It just becomes slower, heavier, and harder to scale without you noticing. I have come to realize most developers aren’t “bad at Next.js” They’re just building it with a React-only mindset. I only really understood this after looking back at one of my own apps and seeing what I was actually doing. #FullStackDevelopment #NextJS #NestJS #TailwindCSS #StartupTech #WebDevelopment #AIIntegration #SoftwareEngineering #DigitalSolutions

🚀 Is Your React App Slowing Down? It Might Be Your Bundle Size One silent performance killer in React apps is a large JavaScript bundle. The bigger your bundle, the longer it takes to: Load ⏳ Parse 🧠 Execute ⚙️ And users? They feel it immediately. 💡 The Fix: Code Splitting + Lazy Loading Instead of shipping your entire app at once… 👉 Load only what the user needs, when they need it. 🧩 Code Splitting Break your app into smaller chunks. Each route or feature becomes its own bundle instead of one massive file. ⚡ Lazy Loading with React.lazy Load components on demand: const CityList = React.lazy(() => import("./CityList")); 🎯 Use with Suspense <Suspense fallback={<Spinner />}> <CityList /> </Suspense> 👉 Now your component loads only when needed, not upfront. 🛣️ Route-Based Splitting (Best Practice) Perfect for pages: const Home = React.lazy(() => import("./pages/Home")); const Product = React.lazy(() => import("./pages/Product")); Users only download the page they visit 👇 Not your entire app. 🔥 Why This Matters ✅ Faster initial load time ✅ Better performance on low-end devices ✅ Improved user experience ✅ Lower data usage 🧠 Pro Tip Don’t lazy load everything. 👉 Lazy load: Pages Heavy components (charts, maps, editors) 👉 Don’t lazy load: Small reusable components (buttons, inputs) 🧩 Final Thought Performance isn’t just about writing code… It’s about when your code loads. Ship less. Load smarter. Scale better. #React #WebPerformance #Frontend #JavaScript #CodeSplitting #LazyLoading #SoftwareEngineering