Nidhi Jagga’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

🚨 𝗥𝗲𝗮𝗰𝘁 𝗥𝗲𝗻𝗱𝗲𝗿𝗶𝗻𝗴 𝗧𝘄𝗶𝗰𝗲? 𝗜𝘁’𝘀 𝗡𝗼𝘁 𝗮 𝗕𝘂𝗴 — 𝗜𝘁’𝘀 𝗮 𝗙𝗲𝗮𝘁𝘂𝗿𝗲 You start your app in development mode… And suddenly notice: 👉 Components rendering twice 👉 API calls firing twice It feels like something is broken 😅 But actually… everything is working exactly as intended. --- 💡 In development, React’s Strict Mode deliberately runs certain lifecycle methods twice. Why does it do that? 👉 To expose hidden issues in your code early --- Here’s what React is testing for: • Side effects happening during render • Missing cleanup logic in useEffect • Code that isn’t safe to run multiple times For instance: If your useEffect directly triggers an API call without safeguards… 👉 You’ll immediately see duplicate requests And that’s React pointing out a potential problem. --- ⚠️ Key thing to remember: 👉 This behavior only happens in development 👉 In production, everything runs just once --- 🚀 The mindset shift: Don’t try to stop the double execution. 👉 Instead, write code that behaves correctly even if it runs multiple times Because in real-world applications: 👉 Reliable code matters more than code that “just works once” --- So next time your component renders twice… Relax 😄 React is helping you build stronger, more predictable applications. Have you run into this before? 👇 #ReactJS #Frontend #JavaScript #WebDev #SoftwareEngineering #Debugging #CleanCode

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

React.memo doesn't prevent re-renders. It just changes why they happen. ⚠️ You think it's optimized. The Profiler says otherwise. 𝗧𝗵𝗲 𝗺𝗼𝘀𝘁 𝗰𝗼𝗺𝗺𝗼𝗻 𝗺𝗶𝘀𝘁𝗮𝗸𝗲: function Parent() { const config = { theme: 'dark' }; // new object → new reference const handleClick = () => console.log('clicked'); // new function → new reference return <Child config={config} onClick={handleClick} />; } const Child = React.memo(({ config, onClick }) => { return <button onClick={onClick}>{config.theme}</button>; }); React.memo does a shallow comparison. config and handleClick are new references on every render — so Child re-renders every time. The memo did nothing. 𝗧𝗵𝗲 𝗳𝗶𝘅 — 𝘀𝘁𝗮𝗯𝗶𝗹𝗶𝘀𝗲 𝘁𝗵𝗲 𝗿𝗲𝗳𝗲𝗿𝗲𝗻𝗰𝗲𝘀: function Parent() { const config = useMemo(() => ({ theme: 'dark' }), []); const handleClick = useCallback(() => console.log('clicked'), []); return <Child config={config} onClick={handleClick} />; } Stable UI requires stable references. 𝗪𝗵𝗲𝗻 𝗥𝗲𝗮𝗰𝘁.𝗺𝗲𝗺𝗼 𝗶𝘀 𝗮𝗰𝘁𝘂𝗮𝗹𝗹𝘆 𝘄𝗼𝗿𝘁𝗵 𝗶𝘁: 1️⃣ 𝗣𝗿𝗼𝗽𝘀 𝗮𝗿𝗲 𝗽𝗿𝗶𝗺𝗶𝘁𝗶𝘃𝗲𝘀 𝗼𝗿 𝘀𝘁𝗮𝗯𝗶𝗹𝗶𝘀𝗲𝗱 𝗿𝗲𝗳𝗲𝗿𝗲𝗻𝗰𝗲𝘀 Objects and functions without memoization = wasted effort. Strings, numbers, booleans compare correctly by default. 2️⃣ 𝗧𝗵𝗲 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁 𝗶𝘀 𝗴𝗲𝗻𝘂𝗶𝗻𝗲𝗹𝘆 𝗲𝘅𝗽𝗲𝗻𝘀𝗶𝘃𝗲 𝘁𝗼 𝗿𝗲𝗻𝗱𝗲𝗿 If the render is cheap, the comparison is the bottleneck. 3️⃣ 𝗬𝗼𝘂 𝗺𝗲𝗮𝘀𝘂𝗿𝗲𝗱 𝗶𝘁 𝗳𝗶𝗿𝘀𝘁 If you didn't measure it, you didn't optimize it. Open the Profiler. Find the actual bottleneck before reaching for the API. ⚠️ React.memo without stable references is optimisation theatre. It looks like performance work. It isn't. 🎯 𝗧𝗵𝗲 𝗧𝗮𝗸𝗲𝗮𝘄𝗮𝘆 Memoisation is a tool, not a default. Reach for the Profiler before you reach for the API. 💬 Where did React.memo fool you into thinking something was optimized? Drop it below. 👇 #ReactJS #SoftwareEngineering #WebDev #FrontendEngineering #JavaScript

Stop disabling the exhaustive-deps linter in your React Effects ⚛️. we all did the same dirty hack: // eslint-disable-next-line 👇. It is the most common frustrating scenario in React development: You write a useEffect to connect to a websocket or track an analytics event. Inside that effect, you need to read the current value of a state variable—like a shopping cart count or a UI theme. But the moment you read that state, the React linter screams at you to add it to the dependency array. If you add it, your effect re-runs every time the state changes (destroying your websocket connection!). If you don't add it, your build fails. So, we all did the same dirty hack: // eslint-disable-next-line. React finally solves this permanently with useEffectEvent. ❌ The Legacy Way (eslint-disable): Forces you to break the rules of React. Creates a massive risk for stale closures and hidden bugs. Makes your code harder to maintain and review. ✅ The Modern Way (useEffectEvent): Extracts your "event" logic cleanly out of your "lifecycle" logic! • Always Fresh: It guarantees your callback will always read the absolute latest props and state. • Non-Reactive: It is intentionally ignored by the dependency array. It will never cause your useEffect to re-run. • Clean Code: You can finally turn your linter rules back on and trust your dependencies again. The Shift: We are moving away from fighting the framework and using dedicated primitives to separate reactive synchronization from non-reactive events. #ReactJS #React19 #WebDevelopment #Frontend #JavaScript #CleanCode #SoftwareEngineering #TechTips #WebDev #WebPerf #Tips #DevTips #ReactTips #FrontendDeveloper #DeveloperTips

I just discovered something that changed how I build with Next.js. Claude can't see your browser. That means when you say "fix the error" it has no idea what error you mean. The Next.js team built their entire v16 release around this problem. Here's what they built (and how it changes everything for us): → MCP integration that exposes runtime errors, routes, and component state directly to Claude → AGENTS.md : a file that tells Claude to read the actual bundled docs before writing a single line of code → Browser log forwarding to the terminal so Claude gets the real error context I've been using this workflow for 3 months. Here's what actually works: 1. Drop a CLAUDE.md at your project root   Your architecture, naming conventions, folder structure. Claude stops guessing. 2. Give Claude scope, not essays   "Add auth to the login page" beats "build the whole auth system" 3. Paste the full error context    file path + line + surrounding code. Not just the error message. 4. Ask Claude to review its own output    "check this for Next.js anti-patterns before I ship" catches 80% of issues 5. One feature at a time   the context window is your most valuable resource. Don't burn it on 10 things at once. The developers winning with AI aren't the ones prompting harder. They're the ones who understand how the model actually sees their codebase. Next.js + Claude Code is the strongest solo dev workflow I've used. And it keeps getting better. #NextJS #ClaudeCode #FrontendDev #AITools #WebDevelopment #React #DevWorkflow

#WebDevSaturdays [React Insight #3] ⚛️🔄 One of the most confusing experiences for React developers happens in development mode. You write a 𝘂𝘀𝗲𝗘𝗳𝗳𝗲𝗰𝘁, expect it to run once, and suddenly it runs twice. Logs duplicate. API calls fire twice. It feels like a bug. It is not. React Strict Mode intentionally double-invokes certain lifecycle behaviors, including effects. The goal is to simulate mounting and unmounting cycles to detect unsafe patterns. Here is why this matters. Effects often contain side effects such as API calls, subscriptions, or DOM mutations. If those effects assume they run only once, they can leak resources or create inconsistent state. By running them twice in development, React exposes these hidden assumptions. Where issues typically appear. 1️⃣ Effects that trigger API calls without idempotency. 2️⃣ Subscriptions without proper cleanup. 3️⃣ Logic that depends on “run once” behavior. Reliable code should tolerate re-execution. perceived correctness comes from resilience, not from assumptions about lifecycle timing. In production, React does not double-run effects. But the bugs discovered during development are very real. Next time your effect runs twice, ask yourself. is React misbehaving, or is it showing me a flaw I would have missed. #React #WebDev #Frontend #JavaScript #DevTips

🚨 𝗪𝗵𝘆 𝗬𝗼𝘂𝗿 𝗥𝗲𝗮𝗰𝘁 𝘂𝘀𝗲𝗘𝗳𝗳𝗲𝗰𝘁 𝗥𝘂𝗻𝘀 𝗠𝘂𝗹𝘁𝗶𝗽𝗹𝗲 𝗧𝗶𝗺𝗲𝘀 (𝗔𝗻𝗱 𝗛𝗼𝘄 𝘁𝗼 𝗙𝗶𝘅 𝗜𝘁 𝗪𝗶𝘁𝗵𝗼𝘂𝘁 𝗕𝗿𝗲𝗮𝗸𝗶𝗻𝗴 𝗟𝗼𝗴𝗶𝗰) You write a simple `𝘂𝘀𝗲𝗘𝗳𝗳𝗲𝗰𝘁`… But your API gets called twice. 🤯 You check everything—dependencies, logic, structure. Still happens. 👉 If you're using 𝗥𝗲𝗮𝗰𝘁 𝟭𝟴+, this is likely due to 𝗦𝘁𝗿𝗶𝗰𝘁 𝗠𝗼𝗱𝗲 in development. React intentionally runs effects twice to detect side effects and ensure your logic is reliable. 💡 𝗜𝗺𝗽𝗼𝗿𝘁𝗮𝗻𝘁: This doesn’t happen in production. It’s just a dev safety check. ✅ 𝗪𝗵𝗮𝘁 𝘆𝗼𝘂 𝘀𝗵𝗼𝘂𝗹𝗱 𝗱𝗼 𝗶𝗻𝘀𝘁𝗲𝗮𝗱: • Write idempotent effects (safe to run multiple times) • Add proper cleanup (abort fetch, remove listeners) • Avoid relying on single execution assumptions ⚠️ Don’t disable Strict Mode blindly—it’s helping you catch hidden bugs early. 💬 Have you faced this issue before? How did you handle it? #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #ReactTips #SoftwareEngineering

Hello Memebers.... Today, I finally integrated my website’s frontend with the backend, and it was quite a challenge. Coming from a frontend background, I initially struggled with how the backend actually reads and manages data. To solve this, I started learning backend alongside it. Understanding how GET, POST, and DELETE operations work was a huge help. My takeaways from today: Basics are everything: If your fundamentals are clear, you won’t face much trouble. However, moving from tutorials to a "Real Project" is where things actually get difficult. The "Blame Game": I finally experienced the classic developer saying: "My frontend is fine; the problem must be in the backend!" 😂 But in reality, the issue was in how I was fetching the data. Advice for new developers: Don’t just stick to one side. Having a little knowledge of every part of the stack makes integration much easier and helps you understand the full flow. Step by step, keep building. #FullStackDevelopment #WebDev #CodingJourney #BuildInPublic #JavaScript #SoftwareEngineering