JavaScript Async Doesn't Mean Parallel, It's Scheduled

🚀 Why React doesn’t update the DOM the way you think Most developers say: 👉 “State changed → UI updated” But internally, React does something smarter. 📌 It uses Reconciliation (Diffing Algorithm) Instead of re-rendering everything: • React compares previous Virtual DOM vs new Virtual DOM • Finds only the changed parts • Updates only those nodes in real DOM ⚡ Why this matters: Even small mistakes can break optimization: ❌ Changing keys in lists unnecessarily ❌ Recreating components instead of updating 💡 Real tip: 👉 Always use stable & unique keys in lists 👉 Avoid random keys like Math.random() Small detail. Big performance impact. #JavaScript #WebDevelopment #FrontendDeveloper #ReactDeveloper #UIEngineering #SoftwareEngineering #Coding #Programming #TechCommunity #DevCommunity #CodeNewbie #BuildInPublic #PerformanceOptimization #CleanCode #ScalableSystems #UserExperience #UIDesign #WebPerf #BrowserRendering #TechCareers #Developers #LearnToCode #SoftwareDeveloper #ModernWeb #FrontendEngineering #Debugging #CodeQuality

React is not slow. Your rendering strategy is. Here’s what most developers miss 👇 Every state change: → Re-runs component → Recreates functions → May trigger child re-renders Problem: Too many unnecessary renders. Solution: ✔ Keep state close ✔ Split components ✔ Avoid unnecessary updates Insight: Performance is about controlling renders. Not adding more hooks. #ReactJS #Frontend #Performance #JavaScript #SoftwareEngineering #WebDevelopment #Engineering #Optimization #Programming #Tech

🚀 Understanding the Event Loop in Node.js — The Heart of Asynchronous Magic If you’ve ever wondered how Node.js handles thousands of requests without breaking a sweat, the answer lies in its Event Loop 🔁 At its core, Node.js operates on a single-threaded, non-blocking I/O model. But how does it manage multiple operations at once? That’s where the event loop comes in. 👉 What is the Event Loop? It’s a mechanism that continuously checks the call stack and the callback queue. If the call stack is empty, it pushes queued callbacks into the stack for execution. 👉 Key Phases of the Event Loop: Timers – Executes callbacks scheduled by setTimeout() and setInterval() I/O Callbacks – Handles system-level callbacks Idle, Prepare – Internal use Poll Phase – Retrieves new I/O events Check Phase – Executes setImmediate() callbacks Close Callbacks – Handles closing events (e.g., sockets) 👉 Why it matters: ✔ Efficient handling of concurrent requests ✔ No thread blocking = better scalability ✔ Perfect for real-time apps like chat, streaming, APIs 💡 Pro Tip: Understanding the difference between setTimeout, setImmediate, and process.nextTick() can level up your async programming game. Node.js may be single-threaded, but with the event loop, it behaves like a multitasking powerhouse 💪 #NodeJS #JavaScript #BackendDevelopment #EventLoop #AsyncProgramming #WebDevelopment

⚛️ A small mistake in React cost us performance… here’s what happened. Hey devs 👋 We had a dashboard where everything looked fine… until users increased. Suddenly: ❌ UI started lagging ❌ Filters became slow ❌ Re-renders everywhere 👉 The issue? We were passing fresh objects in props on every render. Something like this: <Child data={{ value: count }} /> Looks harmless… right? 💥 But every render = new object reference → child re-render 💡 What fixed it: ✔ Memoizing data with useMemo ✔ Avoiding inline object creation ✔ Using React.memo properly ⚡ Lesson: React doesn’t compare values… it compares references. Small mistakes → big performance issues. Have you ever faced unnecessary re-renders like this? #reactjs #frontend #performance #javascript #webdevelopment #fullstack #softwareengineering #Coding #TechCareers #Programming #success

Mastering React State with Hooks Ever felt like your React components are getting cluttered with too much state logic? Here’s a simple idea that can seriously clean things up: Custom Hooks What’s the big deal? Custom hooks let you extract and reuse stateful logic across components. Instead of repeating the same `useState` and `useEffect` logic everywhere, you write it once—and reuse it. Can they really halve your code? In many cases… YES. Imagine this: Instead of writing the same logic in 5 components, you move it into a custom hook like `useFetchData()` or `useFormHandler()`. Now you: Reduce duplication Make components cleaner Improve readability Make debugging easier Simple Example Before: Each component handles its own API call logic After: One custom hook handles everything Components just use it Why you should start using them Keeps your code DRY (Don’t Repeat Yourself) Makes scaling your app easier Encourages better structure Pro Tip Start small. Pick one repeated logic (like form handling or API calls) and convert it into a custom hook. #React #WebDevelopment #Frontend #JavaScript #Coding #SoftwareDevelopment

Why does React feel complicated? It’s not because it’s hard. It’s because we over-optimize everything. With React, devs start thinking about performance too early: - memo everywhere - useCallback everywhere - global state for things that don’t need it Now the code is harder to read, harder to debug, and ironically… not faster. Most apps don’t need that level of optimization. They need clarity. React becomes simple again when you stop trying to be clever. Write straightforward components. Let it re-render. Optimize only when something is actually slow. React isn’t complicated. Overengineering is. #reactjs #javascript #webdevelopment #frontend #softwareengineering #programming

setState does not work as you expect Do you think setState works like this: setCount(1) console.log(count) // should be 1, right? Wrong. It's still 0 (or the prev value). And if you don't understand WHY... You'll spend hours debugging something that isn't even a bug. This is Post 6 of the series: 𝗥𝗲𝗮𝗰𝘁 𝗨𝗻𝗱𝗲𝗿 𝘁𝗵𝗲 𝗛𝗼𝗼𝗱 Where I explain what React is actually doing behind the scenes. Here's what's actually happening 👇 setState doesn't update state. It queues a request to React. React then decides WHEN to process it. Not your code. React. That's why the value after setState is still the old one... because the component hasn't re-rendered yet. Now here's where it gets interesting. Call setState 3 times in one click? You'd expect 3 re-renders. React does it in 1. That's called Batching React's built-in performance superpower. It groups all your updates, processes them together, and re-renders once. But batching also leads to one of the most confusing bugs beginners face: setCount(count + 1) setCount(count + 1) // Expected: 2 // Actual: 1 😐 Both calls read the SAME stale snapshot of count. So React queues the same value twice. How to fix this? setCount(c => c + 1) setCount(c => c + 1) // Now it's: 2 ✅ Functional updates always get the latest queued value, not the stale snapshot. One tiny change in how you write setState. Massive impact on how your app behaves. Follow Farhaan Shaikh if you want to understand React more deeply. 👉 Read the previous post: Using index as key is dangerous in list: https://lnkd.in/dPQyScAT #ReactJS #JavaScript #WebDevelopment #Frontend #BuildInPublic #LearnInPublic #ReactUnderTheHood #FrontendDeveloper #Programming #TechStudent

⚛️ Struggling with unexpected bugs in React? Chances are… it’s your useEffect 👀 useEffect is powerful — but only when used correctly. Here’s what every React developer should know: 🔹 Runs After Render It executes after every render (unless controlled properly). 🔹 Dependency Array Matters Missing dependencies = bugs Too many dependencies = unnecessary re-renders 🔹 Perfect for Side Effects API calls 🌐, event listeners 🎧, timers ⏱️ — all handled here. 🔹 Cleanup is Important Avoid memory leaks by returning a cleanup function. 🔹 Don’t Overuse It Not everything needs useEffect. Keep logic simple. 👉 Mastering useEffect = cleaner & bug-free apps. 🚀 Keep learning. Keep building. . . . . . . #Reactjs #Frontenddevelopment #Javascript #Webdevelopment #Coding #Developers #Programming #Softwaredevelopment #Reacthooks #Learning #Tech