Infinite API Calls: The Silent Killer of Your App

I struggled with this React concept more than I expected… 👇 👉 Why are my API calls running twice? ⚙️ What you’ll notice You open your network tab and suddenly see this: api/me → called twice api/roles → called twice api/permissions → called twice Just like in the screenshot 👇 Same request, duplicated… again and again. ⚙️ What’s actually happening In React (development mode), if your app is wrapped in Strict Mode, React will run effects twice on purpose. useEffect(() => { fetch("/api/users") .then(res => res.json()) .then(setUsers); }, []); Even though it looks like it should run once… it doesn’t (in dev). 🧠 What’s going on under the hood React basically does a quick cycle: mount → unmount → remount Why? To catch hidden side effects To check if cleanup is handled properly To make sure your logic doesn’t break on re-renders So if your API call runs twice, React is just making sure your code can handle it. 💡 The important part This only happens in development Production behaves normally (runs once) Your side effects should be safe to run multiple times 🚀 Final thought If your network tab looks “noisy” like the screenshot, it’s not React being broken — it’s React being careful. And once you understand this, debugging becomes a lot less confusing. #React #Frontend #JavaScript #WebDevelopment #ReactJS #SoftwareEngineering

𝐈𝐬 𝐲𝐨𝐮𝐫 `𝐮𝐬𝐞𝐄𝐟𝐟𝐞𝐜𝐭` 𝐫𝐮𝐧𝐧𝐢𝐧𝐠 𝐰𝐡𝐞𝐧 𝐢𝐭 𝐬𝐡𝐨𝐮𝐥𝐝𝐧'𝐭? 𝐓𝐡𝐞 𝐜𝐮𝐥𝐩𝐫𝐢𝐭 𝐦𝐢𝐠𝐡𝐭 𝐛𝐞 𝐦𝐨𝐫𝐞 𝐬𝐮𝐛𝐭𝐥𝐞 𝐭𝐡𝐚𝐧 𝐲𝐨𝐮 𝐭𝐡𝐢𝐧𝐤. I just spent a frustrating hour debugging a seemingly random data refetch in a React component, only to trace it back to a non-primitive dependency in my `useEffect` array. When you pass an object or a function created inside your component directly into `useEffect`'s dependency array, React performs a reference equality check. Even if the contents of your object or the logic of your function haven't changed, its reference is new on every render. This forces your effect to re-run unnecessarily. Here's the common trap: ```javascript // 🚨 Problematic: 'config' object reference changes on every render const MyComponent = ({ id }) => { const config = { userId: id, status: 'active' }; useEffect(() => { fetchData(config); }, [config]); // 💥 Effect re-runs even if 'id' hasn't changed // ... }; ``` A cleaner, more performant way is to stabilize those references. For configuration objects, `useMemo` is your friend: ```javascript // ✅ Solution: 'memoizedConfig' reference is stable as long as 'id' is const MyComponent = ({ id }) => { const memoizedConfig = useMemo(() => ({ userId: id, status: 'active' }), [id]); useEffect(() => { fetchData(memoizedConfig); }, [memoizedConfig]); // ... }; ``` This prevents wasted renders and unnecessary side effects, keeping your app snappier and less buggy. It's often the small details in `useEffect` that lead to the biggest headaches! Have you ever battled a similar `useEffect` dependency bug? What was your fix? #ReactJS #FrontendDevelopment #JavaScript #WebDev #ReactHooks

Most React developers are still thinking in a client-first way — and that’s becoming a problem. Server-first React is quietly changing how we build applications. The traditional approach: - Fetch in useEffect - Move data through APIs (JSON) - Render on the client This is no longer the default in modern React + Next.js. What’s changing: - Server Components handle data and rendering - Client Components are used only for interactivity - UI can be streamed directly from the server - Hydration is selective, not global Impact: - Less JavaScript sent to the browser - Reduced reliance on client-side state - Better performance by default - Simpler data flow (often without an extra API layer) A useful mental model: Server = data + structure Client = interaction This isn’t just a feature update - it’s a shift in architecture. If you’re still using useEffect primarily for data fetching, it may be time to rethink how your React apps are structured. #React #Frontend #Fullstack #JavaScript #WebDevelopment

🚀 Custom Hooks in React — Write Once, Reuse Everywhere As your React app grows… 👉 Logic starts repeating 👉 Components become messy 👉 Code becomes harder to maintain That’s where Custom Hooks come in. 💡 What are Custom Hooks? Custom Hooks are reusable functions that let you extract and share logic between components. 👉 Just like built-in hooks—but created by you ⚙️ Basic Example function useCounter() { const [count, setCount] = useState(0); const increment = () => setCount(c => c + 1); return { count, increment }; } 👉 Use it anywhere: const { count, increment } = useCounter(); 🧠 How it works ✔ Uses existing hooks (useState, useEffect, etc.) ✔ Encapsulates logic ✔ Returns reusable values/functions 🧩 Real-world use cases ✔ API fetching logic (useFetch) ✔ Form handling (useForm) ✔ Debouncing inputs (useDebounce) ✔ Authentication logic (useAuth) 🔥 Why Custom Hooks Matter 👉 Without them: ❌ Duplicate logic across components ❌ Hard to maintain code 👉 With them: ✅ Clean components ✅ Reusable logic ✅ Better scalability 🔥 Best Practices (Most developers miss this!) ✅ Prefix with “use” (important for React rules) ✅ Keep hooks focused on one responsibility ✅ Avoid tightly coupling with UI ❌ Don’t over-abstract too early ⚠️ Common Mistake // ❌ Mixing UI + logic function useData() { return <div>Data</div>; } 👉 Hooks should return data/logic—not JSX 💬 Pro Insight (Senior Thinking) 👉 Components = UI 👉 Hooks = Logic 👉 Clean separation = scalable architecture 📌 Save this post & follow for more deep frontend insights! 📅 Day 18/100 #ReactJS #FrontendDevelopment #JavaScript #ReactHooks #CodeQuality #SoftwareEngineering #100DaysOfCode 🚀

Your app has amnesia. Every refresh loses the user's context. Here's why. Every frontend developer has done this at least once — stored filters, pagination, or active tabs in component state. Works perfectly. Until a user refreshes. Or copies the URL. Or hits the back button. Gone. A QA engineer finds a bug in a data dashboard. Spends 20 minutes setting up filters — date range, region, metric type — and sends the URL to the dev. The dev opens it. Empty table. Default state. Not a single filter survived. What should have been a simple link became a 10-step reproduction guide. The usual fix is localStorage. But it solves nothing the moment another person is involved. A user shares a filtered view — wrong results. An analyst sends a dashboard link — everyone sees a different default. The URL travels with the user. localStorage stays on their machine. The mistake I see most often Treating URL sync as an afterthought. You update state, then try to mirror it to the URL. Now you have two sources of truth fighting each other. Race conditions, stale renders, a day of debugging something that shouldn't exist. Read from the URL first. Write to the URL only. Let everything else derive from it. One caveat: every filter change pushes a new entry into browser history by default. A user tweaking 10 filters gets 10 back-button steps before they leave the page. Replace the current entry instead of stacking a new one — the back button should feel like leaving, not time travel through your filter history. The URL was always meant to be the address of a moment, not just a page. It's not a React feature. It's just the web working as intended. #Frontend #React #WebDev #JavaScript #TypeScript

Most React developers start API calls with useEffect(). It works. Until the project gets bigger. Then suddenly: ❌ Manual loading state ❌ Manual error handling ❌ Duplicate API calls ❌ No caching ❌ Refetch logic becomes messy ❌ Background sync becomes difficult ❌ Race conditions become common And your component starts doing too much. That’s when you realize: useEffect is not a data-fetching solution. It is a side-effect hook. That’s where React Query changes everything. useEffect helps you run effects. React Query helps you manage server state. That difference is huge. Use useEffect() for: ✔ Timers ✔ Event listeners ✔ Subscriptions ✔ External system sync ✔ Simple one-time logic Use React Query for: ✔ API fetching ✔ Response caching ✔ Auto refetching ✔ Pagination ✔ Infinite scroll ✔ Mutations ✔ Background updates ✔ Optimistic UI The biggest mistake is using useEffect like a mini backend framework. It was never designed for that. Better architecture: Client state → useState() / useReducer() Server state → React Query That separation creates: ✔ Cleaner code ✔ Better UX ✔ Faster applications ✔ Less debugging ✔ Predictable state management Good React code is not about using fewer libraries. It is about using the right tool for the right problem. Sometimes the best optimization is removing unnecessary code—not adding more. What do you prefer for API calls in production apps: useEffect() or React Query? 👇 #ReactJS #ReactQuery #useEffect #FrontendDevelopment #JavaScript #StateManagement #WebDevelopment #SoftwareEngineering

🚀 Small Bug, Big Lesson in Full-Stack Development I recently worked on improving a web app by making the user experience smoother — instead of typing long zone names manually, users can now simply search or select from a dropdown list. But during this update, everything broke. The frontend stopped communicating properly with the backend, and the entire feature failed. After digging through the code, checking API responses, and debugging step-by-step, I finally found the issue… A simple variable mismatch: “zone” vs “zones” That tiny inconsistency was enough to break the connection between the frontend and backend API. 🔍 What I learned: - Consistency in naming is critical in full-stack development - Debugging is not about guessing, but tracing data flow carefully - Small changes can introduce unexpected system-wide issues 💡 Fixing this not only restored functionality but also reinforced how important attention to detail is when working across client and server. You can check out the project here: 👉 [https://lnkd.in/dCuCfCsv] #WebDevelopment #JavaScript #NodeJS #FullStackDeveloper #Debugging #SoftwareEngineering #LearningInPublic #Frontend #Backend #CodingJourney

🚨 Why Environment Files are MUST in React Projects? If you're building real-world apps and still NOT using proper environment configuration… you're inviting bugs into production 😅 In every project, we typically have: 👉 Development 👉 Staging (Testing) 👉 Production Now imagine using the SAME API URL or configs everywhere 🤯 Dev APIs in production ❌ Testing configs leaked to users ❌ Wrong analytics / logs ❌ This is where Environment-Based Configuration becomes critical. 💡 What should go into env files? API URLs App configs Feature flags (like enabling new UI) Analytics IDs Logging configs ⚠️ Common mistakes developers make: Not separating env files per environment Forgetting correct build mode (dev/stage/prod) Storing sensitive secrets in frontend env files 👉 In Vite (React), always use VITE_ prefix 👉 Access using import.meta.env 👉 And always build with correct mode When done right, your app becomes: ✔️ Scalable ✔️ Safe ✔️ Easy to manage across environments I’ve explained this with practical examples in my latest video 👇 🎥 https://lnkd.in/g5ca-kcU #ReactJS #Frontend #SystemDesign #JavaScript #WebDevelopment #Coding #SoftwareEngineering #ReactDeveloper

Why Lifting State Up is Important in React? In React, one of the most powerful concepts you’ll come across is "Lifting State Up". It might sound complex at first, but once you get it, your component design improves instantly. 1️⃣What is Lifting State Up? Lifting state up means moving state from a child component to its closest common parent so that multiple components can share and stay in sync with the same data. 2️⃣ Why is it Important? 1️⃣ Single Source of Truth When state is managed in one place, your data stays consistent across components. No more bugs caused by mismatched states. 2️⃣ Better Data Flow React follows a unidirectional data flow (parent ➝ child). Lifting state up helps you stay aligned with React’s core philosophy. 3️⃣ Easier State Management Instead of managing multiple states in different components, you centralize it, making your app easier to debug and maintain. 4️⃣ Component Communication Made Easy Sibling components can’t talk directly. But if you lift the state to a parent, they can communicate via props. 3️⃣Simple Example Imagine two components: -SearchBar -ResultsList Both need access to the same search query. 🔍Instead of keeping state inside SearchBar, lift it up to the parent: -Parent holds query -Pass query & setQuery to SearchBar -Pass query to ResultsList -Now both components stay perfectly in sync. 4️⃣When NOT to Lift State When the state is only used in one component When lifting makes your component tree unnecessarily complex Rule of thumb: Lift state only as much as needed, not more. Final Thoughts Mastering this concept will make you a better React developer. It’s not just about writing code, it’s about designing clean, scalable systems. What do you think? Have you faced issues that were solved by lifting state up? Let’s discuss #React #Frontend #WebDevelopment #JavaScript #ReactJS #Coding

React 19 just mass-deleted half your "optimization" code. And your app got faster because of it. ⚡ For years, React devs have been trained to do one thing — memoize everything. useMemo here. useCallback there. React.memo wrapping every component like bubble wrap. We called it "performance optimization." It was actually performance anxiety. 🧠 The real problem? Most useMemo and useCallback calls do absolutely nothing for performance. They add complexity. They make onboarding painful. And wrong dependency arrays silently break your app. ⚡ React 19 shipped a compiler. Not a plugin. A compiler that automatically figures out: → Which values need memoization → Which components should skip re-renders → Which callbacks are stable All at build time. Zero runtime cost. Zero developer effort. 🔥 Before vs After: React 18: useMemo, useCallback, React.memo everywhere. Dependency arrays at 2 AM. Bugs you can't trace. React 19: Write plain code. The compiler handles the rest. Same performance. Half the code. Zero mental overhead. 🎯 Why this matters: → Junior devs stop guessing where to put useMemo → Code reviews stop being memoization debates → Stale closure bugs just... disappear I removed 23 useMemo/useCallback hooks from one component last week. The diff was -67 lines. It went from "nobody wants to touch this" to "anyone can read this in 30 seconds." The best code isn't the most optimized code. It's the code your entire team ships confidently. React 19 didn't just remove boilerplate. It removed an entire category of bugs. Save this for your team ♻️ #react #javascript #frontend #webdevelopment #softwareengineering #react19 #ES6