JavaScript Event Loop: Understanding Promise Callbacks and UI Rendering

Ever wondered how things actually work behind the scenes in JavaScript? 🤔 This simple concept changed how I think about building apps 👇 👉 A listener is just code that waits… and runs only when something happens. No constant execution. No unnecessary work. Just event → action ⚡ This is not just basic JS — 👉 this is exactly how Chrome works internally 👉 how Browser extensions communicate 👉 how modern apps stay fast and responsive Once you understand listeners, you start thinking in event-driven systems, not just functions. And that’s where real engineering begins 🚀 #javascript #webdevelopment #frontend #softwareengineering #reactjs #chromeextension

Unpopular opinion: useEffect is one of the most misused hooks in React. Most codebases I've worked in fall into the same traps: → Syncing state that could just be derived → Triggering logic that belongs in an event handler → Creating infinite re-render loops nobody wants to debug at 2am The real rule is simple: useEffect is for syncing with external systems — browser APIs, network requests, third-party widgets. That's it. If you're using it to watch one state variable and update another — that's a sign your state model needs a rethink, not another effect. Cleaner effects = easier to reason about = fewer production bugs. Spotted this on X via @alexdanilowicz — and it resonated #React #JavaScript #WebDevelopment #Frontend

Your UI lag is not always React. Sometimes… It’s the JavaScript event loop. Here’s what’s happening 👇 JavaScript is single-threaded. So when you run: → Heavy calculations → Large loops → Sync blocking code You block: ❌ Rendering ❌ User interactions Result: → UI freezes → Clicks feel delayed → App feels slow React can’t help here. Because it runs on the same thread. What works: ✔ Break work into chunks ✔ Use requestIdleCallback / setTimeout ✔ Offload heavy tasks (Web Workers) Key insight: Performance is not just “React optimization”. It’s understanding how the browser executes code. Ignore the event loop… And your UI will suffer. #JavaScript #EventLoop #Frontend #ReactJS #Performance #SoftwareEngineering #WebDevelopment #AdvancedReact #Engineering #Optimization

Headline: 📈 Small Projects, Big Progress. From static HTML pages to dynamic, state-driven interfaces. This To-Do app was a fun way to practice Clean Code principles in Vanilla JS. Key Features: ✅ Add tasks via button or keyboard. ✅ Individual task deletion. ✅ Clean, centered UI for better focus. Next step? Adding LocalStorage so the tasks persist even after a page refresh! 🔄 #LearnToCode #JavaScript #DeveloperJourney #WebDev #PortfolioProject

🚀 useEffect vs useLayoutEffect — One Small Difference, Big Impact! As a React developer, I used to think both hooks were almost the same… until I understood when they run 👇 🔹 useEffect Runs after the browser paints the UI 👉 Non-blocking → Better for performance Perfect for: ✅ API calls ✅ Event listeners ✅ Logging 🔹 useLayoutEffect Runs before the browser paints the UI 👉 Blocking → Can affect performance Used for: ✅ DOM measurements ✅ Layout adjustments ✅ Preventing UI flicker ⚡ The Key Difference: Timing 👉 useLayoutEffect runs first 👉 useEffect runs after paint 💡 Golden Rule Always use useEffect unless you specifically need to measure or modify the DOM before it renders. Understanding this small difference can help you avoid performance issues and UI glitches 👀 💬 Have you ever faced flickering issues or layout bugs in React? #ReactJS #FrontendDevelopment #JavaScript #WebDevelopment #ReactHooks #LearningInPublic

Day 18 — Pos-tI-tUP 📸 A React-based photo posting app where users can upload, edit, and delete posts with images and captions. Tech Stack: • React • Tailwind CSS • react-hook-form Key Concepts Applied: • Lifting state up across components • useRef for programmatic file input • Component composition (Navbar, UploadForm, PostCard) • CRUD operations via state Small project, big learnings. Consistency is the key. 💪 GitHub: https://lnkd.in/gpVakZ8C Live Link: https://lnkd.in/g-edej_E #React #Frontend #WebDev #100DaysOfCode #Day18 #JavaScript

The `useActionState` is a massive quality-of-life update for React developers. Stop juggling useState for every form submission. You no longer need to manually track loading states, success messages, or server errors—React now does it for you. It bridges the gap between your UI and your logic, making your components cleaner and much easier to maintain. Common use cases: ⏺ Adding state to an Action: Effortlessly track the result of any form submission. ⏺ Handling errors: Display server-side or validation errors without extra boilerplate. ⏺ Using with `form` Action props: The standard, built-in way to link forms to logic. ⏺ Using with `useOptimistic` : Combine them for a snappy, "instant" user experience. ⏺ Cancelling queued Actions: Automatically manage multiple rapid-fire submissions. #react #webdevelopment #javascript #hooks

Just shipped my Day 17/30 JavaScript challenge: a fully functional To-Do List app! Built with vanilla JS, this project showcases DOM manipulation, event listeners, and dynamic element creation in action. Features include adding tasks, marking them complete with a strikethrough effect, deleting individual items, and clearing everything at once. The sleek UI is fully responsive and built with pure HTML, CSS, and JavaScript. no frameworks, just core fundamentals. Tech topics covered: querySelector, innerHTML, createElement, addEventListener, and event delegation. From image uploaders to task managers, each project peels back another layer of web development. Check it out live: https://lnkd.in/d34HUqPn #FullStackDeveloper #JavaScript #WebDevelopment #CodeGuru #FrontendDevelopment

🚀 Master React Router in Minutes! Here’s a simple breakdown of everything you need to know: ✅ What is Routing ✅ SPA Concept ✅ Static vs Dynamic Routes ✅ useParams() ✅ Protected Routes 💡 Key Takeaways: React uses SPA (Single Page Application) Routing helps display components based on URL Dynamic routes make apps scalable Protected routes secure your app 📌 If you're learning React, this is a must-know concept! Let me know in comments 👇 What topic should I cover next? #React #WebDevelopment #Frontend #JavaScript #ReactJS #Coding #LearnToCode

React Router is one of the most essential tools when building modern React applications. It allows developers to create multi-page experiences in a single-page application without reloading the browser. With React Router, you can: Navigate between pages smoothly Manage routes efficiently Create dynamic URLs Improve overall user experience Instead of handling navigation manually, React Router gives a structured and scalable way to manage your application’s flow. Learning React Router is a key step toward building real-world React applications. #React #ReactRouter #FrontendDevelopment #JavaScript #WebDevelopment #SPA #Developers