React Performance: Misusing useMemo and useCallback

🎯 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

🚀 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

⚛️ Why Your React App Re-Renders Too Much (And How Senior Devs Fix It) One of the biggest performance killers in React apps is unnecessary re-renders… and most developers don’t even realize it. 👉 Common mistakes: ❌ Passing new object/array props on every render ❌ Inline functions inside components ❌ Not using memoization properly Example: Every render creates a new function → child re-renders again 💡 Senior-Level Fix: ✔ useCallback → memoize functions ✔ useMemo → memoize expensive calculations ✔ React.memo → prevent unnecessary re-renders But here’s the catch 👇 Don’t overuse them. ⚡ Rule: “Optimize only when there is a real performance issue.” Blind optimization can make your code worse. 👉 Pro Tip: Use React DevTools Profiler to identify actual re-render problems. Performance is not about writing more code… it’s about writing smarter code. #reactjs #frontend #performance #javascript #webdevelopment #fullstack #softwareengineering #optimization

Most React devs are still making users wait for the server. 🙄 I was too. Until I found `useOptimistic` in React 19. **What changed:** → UI updates the moment user clicks → No spinner, no waiting, no freeze → If server fails - React auto rolls back to previous state → Zero extra code for error handling This is exactly how Instagram, X, and LinkedIn build their like buttons. The difference between a "good app" and a "feels native" app is this one pattern. `useOptimistic` ships with React 19. No extra install. If you're still on the old pattern - try this today. Drop a 🔥 if this was new to you! What pattern do you use for instant UI feedback? Let me know 👇 #React19 #ReactJS #useOptimistic #Frontend #WebDevelopment #JavaScript #FullStackDeveloper

🚀 **Struggling with slow React/Next.js apps? Here’s a game-changer: Code Splitting** Most apps fail at performance for one simple reason: 👉 They ship *everything* at once. 💡 **Code Splitting in Next.js** fixes this by loading only what’s needed, when it’s needed. ⚙️ **How it works:** * Each page gets its own JavaScript bundle * Users only download code for the page they visit * Shared code is optimized automatically 📦 **Want more control? Use dynamic imports:** ```js import dynamic from 'next/dynamic'; const HeavyComponent = dynamic(() => import('../components/HeavyComponent')); ``` ✨ This means: * Faster initial load ⚡ * Smaller bundle size 📉 * Better user experience 😌 🧠 **Real talk:** Performance isn’t just a “nice to have” anymore—it’s expected. If you're not optimizing your app, you're already behind. 💬 Are you using code splitting in your projects yet? #NextJS #ReactJS #WebPerformance #Frontend #JavaScript #Coding #BuildInPublic

🚀 Just launched: react-state-vitals A zero-config memory & render monitor for React apps. While working on production apps, I kept asking: 👉 Why is this component re-rendering so much? 👉 Which store is growing in memory? 👉 Where is my performance actually going? So I built a tool to make this visible — instantly. 🧠 react-state-vitals gives you a live floating panel in development: • 📊 Store size tracking (Zustand, Context, React Query) • 🔁 Re-render counts per component • 🧬 JS heap usage insights • ⚡ Zero setup — just install and see Think of it as: 👉 “Vitals for your React state & memory” 📦 Try it here: https://lnkd.in/gU692hyT 🔥 Next I’m planning: • DevTools-like overlay • Identify memory-heavy components in real time • Visual performance timeline Would love feedback from fellow devs 🙌 What would you want this to track next? #React #JavaScript #Frontend #WebPerformance #OpenSource #NextJS #Zustand

🚀 Built a React App Using useReducer ⚛️ I recently built a "React Quiz" app to strengthen my understanding of state management in React. 🧠 Key learnings: Managing complex state with useReducer Handling async data (loading questions from a mock API) Managing loading, error, and ready states ⚡ Answer selection & smooth navigation between questions Tracking progress 📊 Completing & restarting the quiz 🔁 Implementing a countdown timer using useEffect ⏱️ 💡 This project helped me understand when to use useReducer over useState for more structured and scalable state logic. 🔗 GitHub Repo: https://lnkd.in/g8VeyXhi Feedback is welcome 🙌 #React #JavaScript #FrontendDevelopment #WebDevelopment #ReactJS #LearningByBuilding

I used to think I understood React… until I had to pass the same state through 3–4 components just to control one small thing 😅 It worked, but it didn’t feel right. So instead of jumping to another tutorial, I tried to actually "understand the problem" and that led me to the Context API. To keep things simple, I built a tiny “bulb toggle” app 💡 At first, everything was prop-based. Then I switched to Context… and the difference was obvious. Now: 1. I’m not passing props through unnecessary layers 2. Components feel more independent 3. The code is easier to read and reason about But I also learned something important while doing this: 👉 Context is helpful, but it’s not a replacement for everything If the state is simple and only needed in a few places, props are still totally fine. Context starts to make sense when multiple parts of your app need the same data. Still early in my journey, but this was one of those small moments where things started to click. If you’ve worked with Context before -> 👉 how do you decide between props, Context, or other state tools? #learninginpublic #reactjs #webdevelopment #javascript #frontenddevelopment

🚨 Stop guessing production bugs. Start seeing them. If you're building modern frontend apps, especially in React, relying on console logs or user complaints is not enough anymore. That’s where Sentry comes in. 💡 What makes Sentry powerful? ✔️ Real-time error tracking ✔️ Detailed stack traces + user context ✔️ Session replay (see what the user actually did!) ✔️ Performance monitoring for slow APIs & renders Instead of: ❌ “User says the app crashed” ❌ “Can’t reproduce the issue” You get: ✅ Exact error + line number ✅ User journey before crash ✅ Environment + device details ⚛️ For React developers Sentry integrates seamlessly with Error Boundaries and gives you visibility into component-level failures. --- 🔥 Real talk: If your app is in production and you’re not using monitoring, you’re basically flying blind. --- 💬 Curious—what tools are you using for error tracking in your frontend apps? #ReactJS #FrontendDevelopment #WebDevelopment #Sentry #Debugging #JavaScript #SoftwareEngineering

🔗 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