Optimizing use() hook in React for stable Promise reuse

Day 7:𝐘𝐨𝐮𝐫 𝐑𝐞𝐚𝐜𝐭 𝐀𝐩𝐩 𝐈𝐬𝐧'𝐭 𝐒𝐥𝐨𝐰. 𝐘𝐨𝐮𝐫 𝐑𝐞𝐧𝐝𝐞𝐫 𝐀𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞 𝐈𝐬. Most performance problems in React aren't caused by heavy computation. They're caused by components re-rendering when they shouldn't. And that's an architecture problem — not a React problem. The 3 silent performance killers: -->State too high in the tree When global state lives at the top, every update re-renders the entire subtree. Move state down. Keep it close to where it's used. -->Everything in one component A component that fetches, transforms, and renders — re-renders entirely for any change. Split responsibilities. Isolate re-renders. -->Server state in global store Storing API responses in Redux/Zustand triggers app-wide re-renders. Server state belongs in React Query or SWR — not your global store. The fix isn't useMemo everywhere. That's patching symptoms. The fix is: ✔ Co-locate state with the component that owns it ✔ Separate server state from UI state ✔ Keep components focused and small ✔ Use React DevTools Profiler before optimizing anything 𝐏𝐞𝐫𝐟𝐨𝐫𝐦𝐚𝐧𝐜𝐞 𝐢𝐬 𝐧𝐨𝐭 𝐚 𝐟𝐞𝐚𝐭𝐮𝐫𝐞 𝐲𝐨𝐮 𝐚𝐝𝐝 𝐚𝐭 𝐭𝐡𝐞 𝐞𝐧𝐝. 𝐈𝐭'𝐬 𝐚 𝐜𝐨𝐧𝐬𝐞𝐪𝐮𝐞𝐧𝐜𝐞 𝐨𝐟 𝐭𝐡𝐞 𝐚𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞 𝐲𝐨𝐮 𝐝𝐞𝐬𝐢𝐠𝐧 𝐟𝐫𝐨𝐦 𝐭𝐡𝐞 𝐬𝐭𝐚𝐫𝐭. 💬 Where have you seen the worst re-render issues in your projects? #ReactJS #Frontend #WebDevelopment #JavaScript #SoftwareArchitecture

Interesting comparison between HTMX and React while implementing the same feature 👀 The article shows how a relatively simple UI feature took 3 days in React but only 3 hours using HTMX ⏱️ It’s a good reminder that technology choices can significantly affect complexity and development time. Sometimes a simpler approach can solve the problem more efficiently than adding additional abstraction layers. It also raises interesting questions about when complexity is actually necessary in system design. Curious to see how approaches like HTMX evolve alongside traditional frontend frameworks. 💡 Always interesting to see how different tools approach the same problem. #webdevelopment #softwareengineering #javascript #frontend #backend https://lnkd.in/ecpfhWgW

Why your Next.js upgrade is throwing searchParams errors ❓. 👇 If you are upgrading an app to Next.js 15 or 16, your dynamic pages are probably throwing errors. For years, we accessed URL queries and route parameters exactly like normal props. But as Next.js pushes toward a fully async rendering model, accessing request-specific data synchronously actually blocks the server from preparing the rest of the page. To fix this, Next.js made dynamic APIs asynchronous. ❌ The Legacy Way (Next.js 14): Reading searchParams directly as an object. This forces the entire component tree to wait for the user's request, preventing the server from pre-rendering the static shell of your page. ✅ The Modern Way (Next.js 15+): You must await the searchParams prop. • Performance: It allows Next.js to start rendering your layout before the dynamic data is even requested. • Future-Proof: This aligns your code with the new React Server Components async architecture. • Clean: It is a simple 1-line syntax update that prevents massive hydration bugs. The Shift: We are moving away from treating the server environment like a synchronous browser window. A technical guide on migrating to Next.js 15 and 16 by resolving searchParams and params errors. Learn why dynamic APIs are now asynchronous and how to await searchParams in your React Server Components to improve performance and prevent rendering bugs. #NextJS #NextJS15 #NextJS16 #ReactJS #WebDevelopment #Frontend #JavaScript #CleanCode #SoftwareEngineering #TechTips #WebDev #CodingTips #FrontendDevelopers

Topic: Stale Closures in React – The Hidden Bug You Don’t See Coming ⚠️ Stale Closures in React – The Bug That Looks Fine… Until It’s Not Your code works. No errors. No warnings. But suddenly… state behaves incorrectly 😐 Welcome to the world of stale closures. 🔹 What is a Stale Closure? When a function captures an old value of state instead of the latest one. 🔹 The Problem const [count, setCount] = useState(0); useEffect(() => { const interval = setInterval(() => { console.log(count); // ❌ always logs old value }, 1000); return () => clearInterval(interval); }, []); 👉 count is stuck at its initial value. 🔹 Why This Happens React closures capture values at render time, not at execution time. 🔹 Solutions ✅ 1. Add dependency useEffect(() => { console.log(count); }, [count]); ✅ 2. Use functional update setCount(prev => prev + 1); ✅ 3. Use useRef for latest value const countRef = useRef(count); countRef.current = count; 💡 Real-World Impact 👉 Timers 👉 WebSockets 👉 Event listeners 👉 Async callbacks 📌 Golden Rule If your logic depends on changing state, make sure it’s not using a stale snapshot. 📸 Daily React tips & visuals: 👉 https://lnkd.in/g7QgUPWX 💬 Have you ever debugged a stale closure issue for hours? 😅 #React #ReactJS #JavaScript #FrontendDevelopment #WebDevelopment #ReactHooks #DeveloperLife

This is subtle but causes real performance issues: ```js // New function reference every render — React remounts the child each time function ParentComponent() { function ChildComponent() { return <div>Child</div>; } return <ChildComponent />; } ``` Every time ParentComponent renders, React sees a brand new component definition. It unmounts and remounts the child — destroying its state and causing unnecessary DOM operations. The fix is simple — define components at the module level: ```js // Stable reference — React correctly reuses the component function ChildComponent() { return <div>Child</div>; } function ParentComponent() { return <ChildComponent />; } ``` This is one of those mistakes that's easy to make and hard to debug when you don't know what to look for. #ReactJS #JavaScript #Frontend #WebDevelopment

Most explanations make React server components sound harder than they actually are but they're not. Simply... React Server Components are just components that run on the server instead of the browser, so they don't send unnecessary JavaScript to the client and only the final rendered output reaches the UI. Say like moving heavy work away from the user's device and handling it where it's more efficient 😎 Behind the scenes, React executes these components on the server, fetches data directly there like from a DB or API without needing extra client side calls, converts the result into a lightweight payload, and streams it to the browser where it gets merged with interactive parts handled by client components. Why this actually matters is simple, less JavaScript in the browser means faster load, smaller bundles, better performance, and your sensitive logic stays on the server while still keeping the UI interactive where needed. Follow Sakshi Jaiswal ✨ for more quality content ;) #Frontend #React #Sakshi_Jaiswal #FullstackDevelopment #javascript #TechTips #ServerComponents #ServerSideRendering #NextJs

If you’re using Next.js 13+, fetching data inside useEffect is often unnecessary. It causes: • Extra client-side waterfalls • Loading flashes • Worse performance // ❌ Old Pattern useEffect(() => { fetch("/api/posts").then(res => res.json()).then(setPosts); }, []); // ✅ Modern Pattern (Server Component) async function Posts() { const posts = await fetch("https://api.com/posts").then(r => r.json()); return <PostList posts={posts} />; } Server Components reduce JS bundle size and improve performance automatically. #NextJS #ReactJS #WebPerformance #FrontendDev #JavaScript

Your frontend .env file is not a safe place for API keys. And most teams don’t realise this until it’s too late. I get why it feels safe. You pull the key out of the code, stick it in .env, add it to .gitignore and move on. Feels responsible. Feels clean. But in Next.js anything you prefix with NEXT_PUBLIC_ gets bundled straight into the client at build time. It ships to the browser. Anyone who opens devtools and digs through your JS bundle can find it sitting right there. The .env file didn’t protect you. It just changed where you typed the key. This is not a bug. It’s how it works. The browser needs to read that value so Next.js puts it in the bundle. But a lot of teams treat the .env file like a vault and never stop to question what actually happens at build time. The real fix is your sensitive keys should never reach the frontend at all. Route those calls through a server side layer. Your BFF, an API route, server actions, whatever fits your setup. The key lives on the server. The browser never sees it. Configuration in .env is fine. Secrets in .env on the frontend is just security theatre. Anyways that’s my two cents. Have you ever worked in a codebase where sensitive keys were just sitting in the bundle? How did that get caught? #NextJS #React #Frontend #WebSecurity #JavaScript #TechLead #WebDevelopment #Sydney

Ever wondered why changing one small thing in React doesn’t re-render the entire UI? 🤔 That’s reconciliation. In React, every update creates a new virtual DOM. But instead of updating everything, React compares the new tree with the previous one - and updates only what changed. Sounds simple, but small mistakes can break performance. 😬 • Missing or unstable keys ➡️ unnecessary re-renders • Recreating objects/functions ➡️ diffing becomes expensive • Large component trees ➡️ slower updates React is fast. But only if we help it. Reconciliation is not magic - it’s an optimization strategy based on assumptions. Understanding it changes how you structure components. 😉 Have you ever fixed a performance issue just by adding proper keys or memoization? #reactjs #frontend #webperformance #javascript #learninginpublic

React Server Components changed how I think about frontend architecture. Here's the mental model I use to decide which to pick: Use SERVER components when: → You need to fetch data directly (no waterfall) → You want to keep secrets out of the client bundle (API keys, DB queries) → The component has no interactivity → You want a smaller JS bundle Use CLIENT components when: → You need useState, useEffect, or event handlers → You're using browser APIs (localStorage, geolocation) → You need real-time updates → You're building interactive UI (modals, forms, sliders) The default should be Server. Only reach for Client when you need it. This one shift alone can cut your JS bundle size by 30–50% on content-heavy apps. #React #NextJS #WebDevelopment #Frontend #JavaScript