Pankaj Sharma’s Post

Stop writing React like it's 2020. These 10 tricks changed how I build apps. I've spent 8+ years building React applications for 50+ clients from startups to enterprise platforms. Along the way, I discovered tricks that most tutorials never teach. Not complex theory, practical patterns that immediately make your code faster, cleaner, and more maintainable. Here's what's inside: → The real difference between useMemo and useCallback → Custom Hooks that eliminate 100+ lines of repeated code → How React.lazy() cut my bundle size from 2.4MB to 340KB → Error Boundaries, because one broken component shouldn't crash your app → 3 useRef tricks you've probably never used → Why using array index as key is a silent bug → Server Components, what every React dev needs to know in 2026 Each slide has real code examples. No fluff. No theory. Just patterns you can copy into your project today. Swipe through all 10 slides >>> Agree or disagree with any of these? Let me know in the comments, I read every single one. ♻ Repost to help a developer friend level up 📌 Save this for your next React project #ReactJS #JavaScript #WebDevelopment #React #NextJS #TypeScript #CodingTips #DevTips #SoftwareEngineering #Frontend #Programming #FullStackDeveloper

🚀 I thought I was optimizing my React app… but I was actually wasting time 😅 In my React projects, I used to spend a lot of time on performance optimization: 🔹 "useMemo" 🔹 "useCallback" 🔹 "React.memo" I thought this was the “right way”. But recently, I learned about the React Compiler. It can automatically handle many optimizations that we used to do manually. That made me realize… 👉 I was spending too much time optimizing things that React can handle for me. --- 🔹 What I learned React is evolving. With the compiler: 👉 Many unnecessary re-renders can be optimized automatically 👉 Less need for manual memoization in many cases But this doesn’t mean we stop thinking as developers. --- 🔹 What still matters We still need to focus on: 👉 Code splitting 👉 Lazy loading 👉 Following React best practices 👉 Writing clean and predictable components And most importantly: 👉 Following React rules properly --- 🔹 Reality check The React Compiler is still evolving and improving, so it’s important to understand where it helps and where manual optimization is still needed. So we should: 👉 Understand optimization concepts 👉 Use tools like React DevTools to analyze performance 👉 Apply manual optimization only when needed --- 💡 My takeaway 👉 Don’t over-optimize early 👉 Understand the problem first 👉 Keep learning and stay updated Because in tech: 👉 What worked yesterday may change today Still learning and improving 💻 How do you approach performance optimization in React? 👇 #ReactJS #FrontendDevelopment #WebDevelopment #PerformanceOptimization #JavaScript #LearningJourney #DeveloperMindset

⚛️ React works with ⚡ Vite in a modern frontend setup. Earlier, I thought building React apps always required heavy bundling and slow refresh. But Vite changes that completely by using native ES modules. Instead of bundling everything at the start, Vite loads only what is needed — making development much faster and smoother. What I understood from this architecture: • ⚡ Instant dev server startup (no waiting time) • 🔁 Hot Module Replacement (see changes instantly without reload) • 🧩 Clear flow: index.html → main.jsx → App.jsx → components • 🧠 Easy-to-manage component-based structure • 📦 Optimized production build with better performance For beginners, this kind of setup reduces confusion and improves learning speed. For developers, it improves productivity and code quality. Understanding tools like Vite is not just about speed — it’s about writing better, scalable frontend applications. 🚀 #React #Vite #FrontendDevelopment #Learning #WebDevelopment #JavaScript

26 questions. The difference between knowing React on paper and surviving a real production codebase. Here are the 26 questions categorized by the depth of experience required: Level 1: The Foundations => How does React’s rendering process work? => What’s the difference between state and props? => What are hooks, and why were they introduced? => What are controlled vs uncontrolled components? => When would you use refs? => How do you handle forms and validations? Level 2: State & Logic => When should you lift state up? => How do you manage complex state in an application? => When would you use useState vs useReducer? => How do useEffect dependencies work? => How do you handle API calls (loading, error, success states)? => How do you manage shared state across components? => Context API vs Redux — when would you use each? Level 3: Performance & Scale => What causes unnecessary re-renders, and how do you prevent them? => What is memoization in React? => When would you use React.memo, useMemo, and useCallback? => How do you structure a scalable React application? => How do you optimize performance in large-scale apps? => What tools do you use to debug performance issues? => How do you secure a React application? => How do you test React components effectively? Level 4: The War Stories => Have you faced an infinite re-render issue? How did you fix it? => Tell me about a complex UI you built recently. => How did you improve performance in a React app? => What’s the hardest bug you’ve fixed in React? => How do you handle 50+ inputs in a single form without lag? Syntax is easy to Google. Deep understanding is hard to fake. #ReactJS #FrontendDevelopment #TechInterviews #JavaScript #WebDevelopment #Developers

⚛️ Why Most React Developers Stay Stuck at “Intermediate” Level 🚧 You know React… You can build components… You understand hooks… But still — something feels missing. Here’s the truth 👇 Most developers stay stuck because they focus on features, not foundations. 🔹 1. You Build UI… But Don’t Think About Architecture Anyone can create components. But structuring a scalable app? That’s real skill. 👉 Ask yourself: Is my code reusable? Is my folder structure scalable? 🔹 2. You Know Hooks… But Not When to Use Them Using useEffect everywhere ≠ good practice ❌ 👉 Learn: When NOT to use useEffect Derived state vs actual state Avoid unnecessary re-renders 🔹 3. You Ignore Performance Until It Breaks 🐢 If your app slows down, it's already too late. 👉 Start early: Memoization Code splitting Virtualization 🔹 4. You Rely Too Much on Tutorials 📺 Tutorials teach how Real growth comes from building & debugging 🔹 5. You Don’t Read Code Written by Others This is underrated. 👉 Explore: Open source projects Senior dev codebases 💡 Real Growth Hack: Stop asking: “How do I build this?” Start asking: “How do I build this better?” That’s the difference between a developer and an engineer 🚀 🔥 Question: What’s one thing that helped you move beyond the intermediate level? #ReactJS #Frontend #WebDevelopment #JavaScript #Programming #Developers #Coding #SoftwareEngineering

I wish someone told me this when I started with React… A few months into building apps, I thought I was doing everything right. Components were working. UI looked fine. Features were shipping. But under the hood? It was a mess. Random bugs. Re-renders I couldn’t explain. Code that worked… until it didn’t. That’s when I realized, React isn’t hard. Bad practices are. Here are some “DON’Ts” that completely changed how I write React: => Don’t mutate state directly, I used to push into arrays and wonder why UI didn’t update properly. => Don’t use index as key, Everything looks fine… until you reorder items and chaos begins. => Don’t create functions inside render unnecessarily, Small mistake, big performance issues in large apps. => Don’t build huge components If your component feels like a novel, it’s already a problem. => Don’t ignore dependency arrays This one silently creates bugs that are painful to debug. => Don’t over optimize early, Using useMemo/useCallback everywhere doesn’t make you smart, just complex. => Don’t skip error handling, Everything works… until the API fails. => Don’t ignore folder structure, Scaling a messy project is a nightmare. Clean React code isn’t about writing more. It’s about avoiding mistakes. If you’re learning React right now, save this, it’ll save you hours. #ReactJS #FrontendDevelopment #JavaScript #WebDevelopment #CleanCode #DeveloperTips #ProgrammingLife #DevCommunity #BuildInPublic #FullStackDeveloper #CodeQuality #LearnInPublic

Why React Apps Feel So Fast (Hint: It’s NOT the DOM) When I first started learning React, I thought: “It directly updates the DOM efficiently.” But that’s not the real magic. The real hero? → Virtual DOM Here’s how it works: 1️⃣ React creates a Virtual DOM (a lightweight copy of the real DOM) 2️⃣ When state changes, React creates a new Virtual DOM 3️⃣ It compares the old vs new (this is called diffing) 4️⃣ Only the changed parts are updated in the real DOM (reconciliation) Result: Instead of reloading the entire page, React updates ONLY what changed. Think of it like this: Imagine updating a document: Rewrite the whole file Just edit the changed lines React chooses the second approach Why this matters: • Better performance • Smoother UI updates • Scalable applications One thing I realized: React is not “fast because of DOM” It’s fast because it avoids unnecessary DOM work If you're learning frontend, understanding this concept changes how you think about UI updates. What was your “aha moment” while learning React? #React #WebDevelopment #Frontend #JavaScript #CodingJourney

Most beginners think React / Next.js is just about writing code… but the real game starts when you understand components. At this stage (Month 5–6), everything changes. You stop building random pages… and start building reusable systems. A button is no longer just a button. It becomes a component you can use anywhere. A simple UI turns into a structured application powered by props, state, and hooks. This is where you learn: ✔ How to break complex UI into small pieces ✔ How to manage data with state & props ✔ How to build dynamic, fast, and scalable apps ✔ How Next.js takes it further with performance (SSR & CSR) This phase separates beginners from real developers. Because real developers don’t just write code… they build smart, reusable, and scalable architectures. 👉 Master components, and you unlock the real power of frontend development. #ReactJS #NextJS #FrontendDevelopment #WebDevelopment #CodingJourney #JavaScript #LearnToCode #DevelopersLife #UIEngineering #TechSkills

Most React developers write custom hooks. But many of them don’t scale. You only realize this when your app grows. At first, hooks feel easy: Fetch data → store state → return it. Everything works… until: → You need the same logic in multiple places → Small changes break multiple screens → Side effects become hard to track → Debugging takes longer than expected The problem? We treat hooks like shortcuts instead of thinking about structure. What works better: → Keep hooks small and focused → Don’t hardcode logic — pass it as input → Separate fetching, logic, and UI → Return consistent values (data, loading, error) → Avoid unexpected side effects Simple mindset shift: Custom hooks are not just helpers. They define how your app handles data and logic. If a hook is poorly designed: → it slows you down later If it’s well designed: → everything becomes easier to scale Some of the React issues I’ve seen, started with bad hooks, not React itself. Have you faced this with custom hooks? #React #Frontend #JavaScript #WebDevelopment #SoftwareEngineering #ReactJS #FrontendDevelopment #Programming #CleanCode #TechLeadership