Rubayed Ahmed Foysal’s Post

🔥 React DevTools: Common Issues & How to Use It Effectively React DevTools is one of the most powerful tools for diagnosing performance issues… but many developers don’t use it correctly. Here’s what I’ve learned 👇 ------------------------------------- 🔍 Common Issues Developers Face: 1️⃣ Not Profiling – Many just inspect components without measuring re-renders or performance. 2️⃣ Ignoring Component Trees – Deep trees hide unnecessary renders. 3️⃣ Overlooking State & Props – Changes in parent state can trigger unexpected child re-renders. 4️⃣ Misreading Flame Charts – Not understanding which operations are expensive. 💡 How to Use React DevTools Effectively: ------------------------------------------------- ✅ Profiler Tab – Measure every render and find bottlenecks. ✅ Highlight Updates – See exactly which components re-render. ✅ Inspect Component Props & State – Check if changes are causing unnecessary renders. ✅ Compare Commits – Analyze how updates affect your tree. ✅ Filter and Focus – Only measure the components that matter. 🚀 Pro Tip: “React DevTools doesn’t just show problems… it tells you exactly where to optimize.” 💬 Your Turn: Which feature of React DevTools helped you most in improving performance? #reactjs #reactdeveloper #webdevelopment #frontend #javascript #reactperformance #profiling #devtools #softwareengineering #frontendengineering #performanceoptimization #cleancode #techlead

𝗠𝗼𝘀𝘁 𝗱𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿𝘀 *𝘂𝘀𝗲* 𝗥𝗲𝗮𝗰𝘁... But very few actually understand it. That’s the difference between writing code and building real products. I created this simple 𝗥𝗲𝗮𝗰𝘁.𝗷𝘀 𝗰𝗵𝗲𝗮𝘁 𝘀𝗵𝗲𝗲𝘁 👇 to help you revise the fundamentals faster. Because no matter how advanced tools get (AI, frameworks, etc.)… Your fundamentals decide your level. If you master these basics: → Components → State & Props → Hooks → Performance You’re already ahead of most developers. 📚 𝗦𝗼𝘂𝗿𝗰𝗲𝘀: W3Schools, JavaScript Mastery, React Don’t just scroll. Save it. Use it. Master it. #ReactJS #Frontend #WebDevelopment #JavaScript #Developers

Stop writing anonymous useEffect functions. Name them. This is one of the smallest changes you can make in React — and one of the most underrated. Most of us write this: useEffect(() => { fetchUser(id); }, [id]); But you can do this: useEffect(function fetchUserOnIdChange() { fetchUser(id); }, [id]); Same behavior. Completely different debugging experience. Here's why it matters: 🔍 Stack traces become readable When something goes wrong inside an effect, your browser's stack trace will show fetchUserOnIdChange instead of just useEffect. You'll know exactly which effect blew up — no more hunting through 8 anonymous functions. 🧠 Self-documenting code A named function is a contract. It tells the next developer (or future you at 11pm) why this effect exists, not just what it does. syncFormWithLocalStorage communicates more than any comment ever could. ⚡ React DevTools clarity The React profiler and DevTools display effect names. When you're profiling performance, named effects let you immediately identify what's running, when, and how often. 🤝 Easier code reviews Reviewers can scan for useEffect(function loadDashboardMetrics and instantly understand intent. No need to read the entire body just to grasp the purpose. The rule of thumb I follow: If an effect is longer than 3 lines or runs conditionally, it gets a name. No exceptions. It takes 2 seconds to type. It saves 20 minutes of debugging. Small habits compound. This is one worth picking up. 🚀 What's a small React habit that's made a big difference for your team? Drop it in the comments 👇 #React #JavaScript #WebDevelopment #FrontendEngineering #CleanCode #ReactJS #SoftwareEngineering

I made React slower trying to optimize it. Wrapped everything in useMemo. Added useCallback everywhere. Felt productive. Performance got worse. Here's what I didn't understand about re-renders 👇 4 things that trigger a re-render: > State change > Prop change > Parent re-renders (even if YOUR props didn't change) > Context update That third one is responsible of unnecessary re-renders I've seen in real codebases. The fix isn't memorizing APIs. It's this order: 1. Profile first Open React DevTools Profiler. Find the actual problem. Takes 2 minutes. 2. Wrap the right components in React.memo Not all of them. Only components that are expensive AND receive stable props. 3. Stabilise your functions with useCallback Without it - new function reference every render --> child always re-renders. Doesn't matter if you have React.memo. 4. useMemo for heavy calculations only Not for "this array map looks expensive." Only when Profiler proves it. The rule I follow now: Don't optimise what you haven't measured. One change in the right place beats 10 changes in the wrong ones. What's the most unnecessary useMemo you've ever written? 😄 #React #JavaScript #Frontend #WebDev

A while back, I noticed something… I was spending way too much time filling the same forms over and over again while testing my projects. Names. Emails. Passwords. Every. Single. Time. At first, I ignored it… but it started slowing me down more than I liked. So I did what most developers do when something gets annoying enough…… I built a solution. That’s how AutoFormX was born. It’s a browser extension that autofills forms instantly, so you can focus on building instead of repetitive typing. 🚀 What it does: • Autofills forms in seconds • Saves reusable test data • Works across different websites • Speeds up development workflow 💡 What I learned: Sometimes the best projects don’t come from big ideas… They come from small frustrations you face every day. 🛠️ Built with: • TypeScript • Next.js • Tailwind CSS • Browser Extension APIs (WXT) 📹 I’ve attached a demo showing how it works. 🔗 Try it here: https://lnkd.in/dNqeGzj4 I’m still improving it, so I’d genuinely love feedback. If you’ve ever built and tested forms… you’ll get why I made this. #buildinpublic #webdevelopment #javascript #productivity #developers #sideproject

Can you cancel a Promise in JavaScript? Short answer: No — but you can cancel the work behind it. A Promise is just a result container, not the async operation itself. Once created, it will resolve or reject — you can’t “stop” it directly. What you can do instead: • Use AbortController → cancels APIs like fetch • Use cancellation flags/tokens → for custom async logic • Clear timers → if work is scheduled (setTimeout) • Ignore results → soft cancel pattern Real-world takeaway: Design your async code to be cancel-aware, not Promise-dependent. This is exactly how modern tools like React Query handle requests under the hood. #JavaScript #Frontend #AsyncProgramming #WebDevelopment #ReactJS #CleanCode

𝐈𝐬 𝐲𝐨𝐮𝐫 `useEffect` 𝐡𝐨𝐨𝐤 𝐫𝐮𝐧𝐧𝐢𝐧𝐠 𝐭𝐨𝐨 𝐨𝐟𝐭𝐞𝐧, 𝐨𝐫 𝐧𝐨𝐭 𝐞𝐧𝐨𝐮𝐠𝐡? 𝐘𝐨𝐮'𝐫𝐞 𝐧𝐨𝐭 𝐚𝐥𝐨𝐧𝐞. I’ve seen countless `useEffect` bugs boil down to one thing: incorrect dependency arrays. It’s deceptively simple, but a missing dependency can lead to stale closures and unexpected behavior, while an unnecessary one can trigger re-renders like crazy. Consider this: if you define a function or object inside your component and use it in `useEffect`, it must be in your dependency array. However, if that function itself isn't memoized with `useCallback` (or the object with `useMemo`), it becomes a new reference on every render, causing your `useEffect` to fire relentlessly. The Fix: 1. Be explicit: List all values from your component scope that `useEffect` uses. ESLint usually flags this for a reason. 2. Memoize functions/objects: If a function or object needs to be a dependency but shouldn't trigger re-runs unless its own dependencies change, wrap it in `useCallback` or `useMemo`. ```javascript // Problem: myApiCall changes every render if not memoized const MyComponent = ({ id }) => { const myApiCall = () => fetch(`/data/${id}`); useEffect(() => { myApiCall(); // myApiCall is a new function on every render }, [myApiCall]); // Infinite loop! } // Solution: const MyComponent = ({ id }) => { const myApiCall = useCallback(() => fetch(`/data/${id}`), [id]); useEffect(() => { myApiCall(); }, [myApiCall]); // Now, myApiCall only changes when 'id' changes } ``` It's a subtle but critical distinction that keeps your React apps performant and predictable. What's the trickiest `useEffect` bug you've ever had to squash? #React #JavaScript #FrontendDevelopment #WebDev #Performance

🔯 You can finally delete <Context.Provider> 👇 For years, the Context API introduced a small but persistent redundancy. We defined a Context object, yet we couldn't render it directly-we had to access the.Provider property every single time. 🔯 React 19 removes this requirement. ❌ The Old Way: UserContext.Provider It often felt like an implementation detail leaking into JSX. Forget Provider, and your app might silently fail or behave unexpectedly. ✅ The Modern Way: <UserContext> The Context object itself is now a valid React component. Just render it directly. Why this matters ❓ 📉 Less Noise - Cleaner JSX, especially with deeply nested providers 🧠 More Intuitive - Matches how we think: "wrap this in UserContext" 💡Note: Note: <Context.Consumer> is also largely dead in favor of the use hook or useContext. Starting in React 19, you can render <SomeContext> as a provider. In older versions of React, use <SomeContext.Provider>. 💬 Have you tried this in your project? 💬 React 18 or 19 — what are you using? 🔗 Learn More: React Context Docs: https://lnkd.in/dbVWdc-C #React #JavaScript #WebDevelopment #Frontend #React19 #ModernReact #ReactHook #CodingLife #DeveloperJourney #SoftwareDeveloper

🚀 Introducing one-global-state — A simpler way to manage global state in React. A small project to solve a common pain point I’ve faced (and I’m sure many of you have too) — global state management in React. We all know tools like Redux or reducer-based patterns are powerful… …but sometimes, they feel like overkill and add bloating for simple use cases 🤯 So I built something minimal, intuitive, and developer-friendly 👇 ✨ one-global-state A tiny utility library that: ✅ Feels just like useState ✅ Eliminates boilerplate ✅ Keeps things simple and predictable ✅ Is easier than most existing alternatives 💡 The idea was straightforward: “What if global state could be as simple as using useState?” No complex setup. No unnecessary abstractions. Just clean and easy state management. 📦 Already seeing traction with 264 weekly downloads 🙌 🔗 GitHub: https://lnkd.in/gjPrNeX4 🔗 NPM: https://lnkd.in/gu6QES8j I’d love to hear your thoughts, feedback, or ideas to improve this further 💬 If you’re tired of over-engineered state solutions, give it a try and let me know what you think! #react #javascript #webdevelopment #opensource #frontend #npm #devtools #buildinpublic

🚀 Crack the Code: The React Lifecycle (Core Level) Ever wondered how React actually manages the life of a component? Whether you’re prepping for a Senior Dev interview or just trying to squash that persistent memory leak, mastering the Lifecycle Phases is your secret weapon. 🛠️ React components are like living organisms: they are born, they grow, and they eventually pass away. 1️⃣ The Birth: Mounting Phase This is where it all begins. React initializes state and builds the initial Virtual DOM. The Hook: useEffect(() => { ... }, []) Pro Tip: Use this phase for initial API calls or setting up subscriptions. If you leave the dependency array empty, it runs exactly once—like a birth certificate! 2️⃣ The Growth: Updating Phase Whenever props or state change, React springs into action. This is where the magic of Diffing happens—React compares the old Virtual DOM with the new one to update only what’s necessary. The Hook: useEffect(() => { ... }, [dependency]) Pro Tip: Always be intentional with your dependency array. Missing a dependency can lead to stale data; adding too many can cause infinite loops! 🔄 3️⃣ The End: Unmounting Phase The most ignored phase, but arguably the most critical for performance. 🧹 The Hook: The Cleanup Function inside useEffect. Why it matters: If you don't clear your setInterval or unsubscribe from a socket here, you’re inviting memory leaks to crash your party. 💡 The "Core Level" Secret: Render vs. Commit To keep your apps buttery smooth, React splits work into two internal phases: Render Phase: Pure calculation. React figures out what changed. It can pause or restart this work if a higher-priority task comes in. Commit Phase: This is where React actually touches the Real DOM. It’s fast, synchronous, and happens in one go. 🧠 The Mental Model Shift In modern React, stop thinking about "methods" and start thinking about Synchronization. useEffect isn't just a lifecycle hook—it’s a tool to synchronize your component with an external system (the API, the DOM, or a Window event). Are you building for performance or just for functionality? Let's discuss in the comments! 👇 #ReactJS #WebDevelopment #FrontendEngineers #CodingTips #JavaScript #SoftwareArchitecture