5 React Native Performance Killers to Check First

5 React Native performance mistakes I fixed in my last 3 projects. Performance issues in React Native apps are almost always the same problems, over and over. 1. Re-rendering entire list components on state change Fix: use FlatList with keyExtractor + React.memo on list items. Measure before and after with Flipper. 2. Storing large objects in component state Fix: move heavy data to a global store (Zustand or Redux) or fetch on-demand. Don't keep it in useState. 3. No image optimization Using full-resolution images in list views. Fix: compress images server-side, use FastImage library for caching. 4. Heavy computation on the JS thread Fix: offload to a web worker or use InteractionManager to defer until after animations complete. 5. Not profiling before optimizing Fixing the wrong things first. Fix: always profile with React DevTools Profiler or Flipper before touching code. Performance is a feature. Users feel it even when they can't name it. Working on a slow React Native app? Comment "PERF" and I'll suggest the 3 things to check first. #ReactNative #AppPerformance #MobileDevelopment #JavaScript #CodeQuality

🚀 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

Your React app isn’t slow because of React. It’s slow because of unnecessary work. Here’s what that actually means 👇 Every render has a cost. And most apps are doing more work than required: ✖ Parent re-renders triggering full subtree updates ✖ Expensive calculations running on every render ✖ Large lists rendered without control ✖ State placed too high in the tree What I focus on instead: ✔ Keep state as close as possible to usage ✔ Control re-render boundaries (not blindly memoizing) ✔ Avoid recalculations unless necessary ✔ Measure before optimizing (React Profiler) Real insight: Performance issues are rarely one big problem. They’re small inefficiencies repeated at scale. Fix the flow → performance improves naturally. That’s how you build systems that feel fast. #ReactJS #WebPerformance #Frontend #JavaScript #SoftwareEngineering #Optimization

💥 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

🚨 Why your React app loads slowly on the first visit Your React app works perfectly. But users complain: "Why does the page take 3–5 seconds to load?" The hidden problem is usually bundle size. When your app grows, all components get bundled into one large JavaScript file. Example: bundle.js → 2.4 MB When a user visits your site, the browser must: 1️⃣ Download the entire bundle 2️⃣ Parse the JavaScript 3️⃣ Execute it Only then the UI appears. This slows down the first load significantly. 💡 The solution is Code Splitting + Lazy Loading. Instead of loading everything at once, load components only when needed. Example: const Dashboard = React.lazy(() => import("./Dashboard")); And wrap it with: <Suspense fallback={<Loader />}> <Dashboard /> </Suspense> Now your app loads only the critical code first. Other components load when the user navigates. Benefits: ✔ Faster initial load ✔ Smaller bundle size ✔ Better performance 💡 Good frontend engineering isn't just about writing features. It's about making sure users don't wait for them to load. #reactjs #frontend #javascript #webperformance #softwareengineering #webdevelopment

I reduced my React app’s bundle size by 60% here’s how I did it. At some point, every React app starts facing performance issues. One major reason is the bundle size. It quietly slows down your app, and many teams don’t notice it early. After doing a proper performance check, I reduced the bundle size from 4.2MB to 1.6MB. At the same time, the page load speed (LCP) improved from 6.8 seconds to 1.9 seconds. Here are the key things that helped: 1. I used a bundle analyzer to see which files and libraries were making the app heavy. This gave me a clear direction on what to fix. 2. I applied tree shaking by using proper imports. This removed a lot of unused code from the final build. 3. I added code splitting using React.lazy() and Suspense, so heavy components like charts and modals load only when needed. 4. I enabled Gzip and Brotli compression on the server, which reduced file size during transfer without changing any code. 5. I reviewed dependencies and replaced heavy libraries like moment.js and lodash with lighter options and native JavaScript. The result was very clear — faster loading, better performance scores, and a smoother user experience. If you’re working with React, optimizing bundle size is not optional. It directly impacts how fast and smooth your app feels to users. For more insightful content checkout below: 🟦 𝑳𝒊𝒏𝒌𝒆𝒅𝑰𝒏 - https://lnkd.in/dwi3tV83 ⬛ 𝑮𝒊𝒕𝑯𝒖𝒃 - https://lnkd.in/dkW958Tj 🟥 𝒀𝒐𝒖𝑻𝒖𝒃𝒆 - https://lnkd.in/dDig2j75 or Priya Frontend Vlogz 🔷 𝐓𝐰𝐢𝐭𝐭𝐞𝐫 - https://lnkd.in/dyfEuJNt   #frontend #javascript #react #reactjs #html #css #typescript #es6 #interviewquestions #interview #interviewpreparation

🌤️ Want to build a real React project but don’t know where to start? This step-by-step tutorial shows how to build a Weather App using React, connect a Weather API, and create a modern UI — perfect for beginners. Instead of just learning theory, start building a practical project for your portfolio. 🎥 Watch the tutorial: https://lnkd.in/grw5HTZ9 🌐 website https://lnkd.in/gp6K4mQS 💬 What was your first React project? Share in the comments! #react #reactprojects #reactjs #webdevelopment #satyaanshsoftech

⚛️ Learning React Hooks - useState I recently explored one of the core concepts of React — Hooks (useState) — and applied it by building a simple Counter App. Here’s what I implemented: ✔️ Managed state using useState ✔️ Built increment & decrement functionality ✔️ Added boundary conditions (0 to 20 limit) ✔️ Understood how React re-renders on state updates Code snippet: let [counter, setCounter] = useState(0); const addValue = () => { setCounter(counter + 1); }; const removeValue = () => { setCounter(counter - 1); }; 💡 This project helped me clearly understand how state works in React and why hooks are so powerful for building interactive UIs. #ReactJS #JavaScript #WebDevelopment #FrontendDevelopment #ReactHooks #LearningInPublic

Passing Parameters in React Native Stack Navigation Sometimes we need to send data from one screen to another, like user ID, name, or product details. In React Native, this can be done easily using navigation.navigate() and route.params. ✔ Pass data while navigating ✔ Receive data in the next screen ✔ Useful for dynamic screens This simple feature helps make apps more interactive and flexible. How often do you pass parameters between screens in your apps? 🤔 #ReactNative #MobileDevelopment #JavaScript #CodingTips

Day 10 #100DaysOfCode 💻 Today I learned the basics of React.js. At first, React felt confusing. There are many new concepts like components and JSX. But I started understanding that React helps us build UI using reusable components. One simple example I tried today: function App() { return ( <h1>Hello React 🚀</h1> ); } export default App; This small component renders a heading on the page. It looks simple, but it shows how React components work. Still learning and exploring. Step by step I will get better. #Akbiplob #ReactJS #JavaScript #WebDevelopment #FrontendDevelopment