React, Async JS, and Testing in Full Stack Development

🚨 Most React performance issues are self-inflicted. Not because React is slow. But because we don’t realize how often our code runs. I learned this the hard way. Everything looked fine in development. But with real data → UI started lagging. No errors. No warnings. Just poor experience. 🔍 The issue? Unnecessary re-renders + recalculations happening on every render. 💡 Fix wasn’t complex: → Memoizing expensive calculations → Stabilizing function references → Avoiding derived state where possible ⚡ Result: Smooth UI. Better performance. Happier users. 🧠 Biggest shift for me: I stopped asking “Is my code correct?” and started asking 👉 “How many times is my code running?” That question alone changes how you write React. What’s one performance issue you’ve faced recently? #ReactJS #FrontendDeveloper #WebPerformance #JavaScript #TypeScript #SoftwareEngineering #Coding

Most developers still cling to Options API habits, but the Composition API is rewriting the rules on code reuse and component organization in Vue. Switching to Composition API helped me break down complex components into smaller, focused functions. I used to struggle with mixins causing unexpected side effects—now, each piece of logic lives in its own composable. This clarity makes debugging and testing easier, especially in bigger projects where scaling code can get messy fast. Plus, sharing logic between components feels cleaner and less error-prone. If you haven't tried converting a component yet, start small: extract reactive state or lifecycle hooks into a composable and import it where needed. How did you handle reusing logic before? Did the transition to Composition API feel smoother or more confusing? #VueJS #JavaScript #FrontendDev #WebDevelopment #ProgrammingTips #CodeReuse #CompositionAPI #DevWorkflow #Technology #SoftwareDevelopment #Coding #VueJS #CompositionAPI #JavaScript #ReusableLogic #Solopreneur #ContentCreator #FounderLife #Intuz

💻 5 React mistakes I stopped making (and it improved my code a lot) When I started with React, I used to write code that worked… But not code that was clean, scalable, and maintainable. Here are 5 mistakes I fixed: ❌ 1. Writing everything in one component 👉 Now I break UI into small reusable components ❌ 2. Ignoring proper state management 👉 Learned when to use useState vs useEffect vs lifting state ❌ 3. Not handling performance 👉 Started using memoization (useMemo, useCallback) ❌ 4. Poor folder structure 👉 Now I follow a clean project structure ❌ 5. Debugging randomly 👉 Now I debug step-by-step with proper logs Small changes… but huge difference in code quality 🚀 Still learning every day 👨💻 Which mistake did you make the most? 😅 #ReactJS #FrontendDevelopment #JavaScript #CleanCode #WebDevelopment #SoftwareEngineer

🚀 Day 970 of #1000DaysOfCode ✨ What is JSX, Why It’s Used & What is TSX If you’ve worked with React, you’ve definitely written JSX — but many developers don’t fully understand what it actually is under the hood. In today’s post, I’ve explained what JSX is, why it’s used, and how it makes writing UI more intuitive by combining JavaScript and HTML-like syntax. I’ve also covered TSX — which is basically JSX with TypeScript — helping you write type-safe components and catch errors early during development. Understanding this difference helps you choose the right approach based on your project needs and team setup. This is one of those concepts that looks simple but plays a big role in how modern React applications are built. If you’re working with React or planning to learn TypeScript, this clarity will really help. 👇 Do you prefer working with JSX or TSX in your projects? #Day970 #learningoftheday #1000daysofcodingchallenge #FrontendDevelopment #WebDevelopment #JavaScript #React #TypeScript #CodingCommunity

Node.js isn’t just a runtime. It’s a quiet shift in how you think about building things. Most of us start coding like we’re stacking bricks — one after another, waiting for each to settle before placing the next. That’s how traditional systems often feel: predictable, but slow… like asking permission at every step. Node.js challenges that mindset. It whispers: “Why wait?” Instead of blocking, it flows. Instead of pausing, it listens. It teaches you to design systems that are less about control and more about coordination. Events happen, responses follow, and everything keeps moving — like a conversation rather than a command. And somewhere in that shift, you realize something deeper: Good systems aren’t the ones that do everything first. They’re the ones that respond at the right time. That’s the philosophy Node.js brings to the table — not speed alone, but responsiveness, scalability, and efficiency in motion. In a world where users expect instant feedback, where millions of requests knock at once, Node.js doesn’t panic. It adapts. Maybe that’s the real lesson here — not just for code, but for how we build anything: 👉 Don’t block progress waiting for perfection. 👉 Stay non-blocking, stay adaptive. 👉 Let things flow, and respond when it matters most. Because sometimes, the smartest system… is the one that knows when not to wait. #NodeJS #JavaScript #BackendDevelopment #ScalableSystems #ProgrammingMindset

When we first created our Core React course, class components were the standard. Over the years, we’ve kept it up to date—adding hooks, modern patterns, and best practices. But this spring, we decided it was time for a 𝗰𝗼𝗺𝗽𝗹𝗲𝘁𝗲 𝗿𝗲𝘄𝗿𝗶𝘁𝗲. Why? Because React has evolved, and so has our approach to teaching it. Our updated 𝗖𝗼𝗿𝗲 𝗥𝗲𝗮𝗰𝘁 𝗖𝗼𝘂𝗿𝘀𝗲 is now 𝗳𝗿𝗲𝘀𝗵, 𝗺𝗼𝗱𝗲𝗿𝗻, 𝗮𝗻𝗱 𝗱𝗲𝗲𝗽𝗹𝘆 𝘁𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹, focusing on the essentials you need to master React today. We don’t just teach how—we dive into the why, because we believe true mastery comes from understanding the layer beneath the abstraction. 𝗪𝗵𝗮𝘁’𝘀 𝗻𝗲𝘄? - A 𝗴𝗿𝗼𝘂𝗻𝗱-𝘂𝗽 𝗿𝗲𝘄𝗿𝗶𝘁𝗲 for React 19 and beyond - 𝗠𝗼𝗿𝗲 "𝘂𝗻𝗱𝗲𝗿 𝘁𝗵𝗲 𝗵𝗼𝗼𝗱" content, including in-depth coverage of React’s 𝗙𝗶𝗯𝗲𝗿 𝗮𝗻𝗱 𝗙𝗮𝗯𝗿𝗶𝗰 𝗮𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 - 𝗡𝗲𝘄 𝗱𝗶𝗮𝗴𝗿𝗮𝗺𝘀 𝗮𝗻𝗱 𝗲𝘅𝗽𝗹𝗮𝗻𝗮𝘁𝗶𝗼𝗻𝘀 to clarify complex concepts - A 𝗽𝗲𝗱𝗮𝗴𝗼𝗴𝗶𝗰𝗮𝗹 𝗳𝗼𝗰𝘂𝘀 on fundamentals, not just examples This isn’t just an update—it’s a 𝗿𝗲𝗶𝗺𝗮𝗴𝗶𝗻𝗲𝗱 𝗹𝗲𝗮𝗿𝗻𝗶𝗻𝗴 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 for developers who want to build a solid foundation in React. 🔗 𝗖𝗵𝗲𝗰𝗸 𝗼𝘂𝘁 𝘁𝗵𝗲 𝗳𝘂𝗹𝗹 𝗼𝘂𝘁𝗹𝗶𝗻𝗲: https://lnkd.in/eaut_UFb 𝗪𝗵𝗮𝘁 𝗱𝗼 𝘆𝗼𝘂 𝘁𝗵𝗶𝗻𝗸 𝗶𝘀 𝘁𝗵𝗲 𝗺𝗼𝘀𝘁 𝗰𝗵𝗮𝗹𝗹𝗲𝗻𝗴𝗶𝗻𝗴 𝗽𝗮𝗿𝘁 𝗼𝗳 𝗹𝗲𝗮𝗿𝗻𝗶𝗻𝗴 𝗥𝗲𝗮𝗰𝘁 𝘁𝗼𝗱𝗮𝘆? Let’s discuss in the comments!. #React #ReactJS #WebDevelopment #Frontend #JavaScript #TechEducation

When we first created our Core React course, class components were the standard. Over the years, we’ve kept it up to date—adding hooks, modern patterns, and best practices. But this spring, we decided it was time for a 𝗰𝗼𝗺𝗽𝗹𝗲𝘁𝗲 𝗿𝗲𝘄𝗿𝗶𝘁𝗲. Why? Because React has evolved, and so has our approach to teaching it. Our updated 𝗖𝗼𝗿𝗲 𝗥𝗲𝗮𝗰𝘁 𝗖𝗼𝘂𝗿𝘀𝗲 is now 𝗳𝗿𝗲𝘀𝗵, 𝗺𝗼𝗱𝗲𝗿𝗻, 𝗮𝗻𝗱 𝗱𝗲𝗲𝗽𝗹𝘆 𝘁𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹, focusing on the essentials you need to master React today. We don’t just teach how—we dive into the why, because we believe true mastery comes from understanding the layer beneath the abstraction. 𝗪𝗵𝗮𝘁’𝘀 𝗻𝗲𝘄? - A 𝗴𝗿𝗼𝘂𝗻𝗱-𝘂𝗽 𝗿𝗲𝘄𝗿𝗶𝘁𝗲 for React 19 and beyond - 𝗠𝗼𝗿𝗲 "𝘂𝗻𝗱𝗲𝗿 𝘁𝗵𝗲 𝗵𝗼𝗼𝗱" content, including in-depth coverage of React’s 𝗙𝗶𝗯𝗲𝗿 𝗮𝗻𝗱 𝗙𝗮𝗯𝗿𝗶𝗰 𝗮𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 - 𝗡𝗲𝘄 𝗱𝗶𝗮𝗴𝗿𝗮𝗺𝘀 𝗮𝗻𝗱 𝗲𝘅𝗽𝗹𝗮𝗻𝗮𝘁𝗶𝗼𝗻𝘀 to clarify complex concepts - A 𝗽𝗲𝗱𝗮𝗴𝗼𝗴𝗶𝗰𝗮𝗹 𝗳𝗼𝗰𝘂𝘀 on fundamentals, not just examples This isn’t just an update—it’s a 𝗿𝗲𝗶𝗺𝗮𝗴𝗶𝗻𝗲𝗱 𝗹𝗲𝗮𝗿𝗻𝗶𝗻𝗴 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 for developers who want to build a solid foundation in React. 🔗 𝗖𝗵𝗲𝗰𝗸 𝗼𝘂𝘁 𝘁𝗵𝗲 𝗳𝘂𝗹𝗹 𝗼𝘂𝘁𝗹𝗶𝗻𝗲: https://lnkd.in/eaut_UFb 𝗪𝗵𝗮𝘁 𝗱𝗼 𝘆𝗼𝘂 𝘁𝗵𝗶𝗻𝗸 𝗶𝘀 𝘁𝗵𝗲 𝗺𝗼𝘀𝘁 𝗰𝗵𝗮𝗹𝗹𝗲𝗻𝗴𝗶𝗻𝗴 𝗽𝗮𝗿𝘁 𝗼𝗳 𝗹𝗲𝗮𝗿𝗻𝗶𝗻𝗴 𝗥𝗲𝗮𝗰𝘁 𝘁𝗼𝗱𝗮𝘆? Let’s discuss in the comments!. #React #ReactJS #WebDevelopment #Frontend #JavaScript #TechEducation

setTimeout(fn, 0) looks simple. Until a Promise shows up… and breaks your expectations. You write this: setTimeout(() => console.log("timeout"), 0); Promise.resolve().then(() => console.log("promise")); And you think: “Timeout has 0 delay… it should run first.” But the output is: ->promise ->timeout So what’s actually happening? Not magic. Not randomness. Just how JavaScript is designed. When your code runs, this is the order: Run all synchronous code Execute all Promises (microtasks) Then execute setTimeout (macrotasks) Now read that again. 👉 Promises are not faster 👉 They are just scheduled differently Here’s the hidden detail most devs miss: Even if your setTimeout is ready… JavaScript will pause it until every single Promise is finished. So in reality: setTimeout(fn, 0) → “Run me later” Promise.then() → “Run me right after this code” That’s why Promises always win. Not because they’re special… But because the event loop always clears microtasks first. The simple mental model: 👉 sync → promises → timers Once you understand this, you stop guessing async behavior… …and start predicting it. #javascript #webdev #eventloop #programming #promises #settimeout #nodejs #javascript #nestjs #backend #softwareengineering

🚀 Starting a 10-part series on React things that make code harder than it needs to be. Not tutorials. Not “10 hooks you should know.” Just real patterns that show up in actual codebases and make simple work more annoying than it should be. Part 1: A lot of React problems are really state problems. Not React itself. Not JSX. Not even hooks most of the time. State living in too many places. Duplicated state. State doing jobs it was never supposed to do. That’s usually when an app starts feeling harder to reason about than it should. The more I work with React, the more I think good frontend code starts with good state decisions. If the state is messy, everything downstream gets harder: debugging feature work testing handoffs even basic collaboration Good React usually feels predictable. And predictable usually starts with state. What’s the most common state mistake you keep seeing? #React #ReactJS #StateManagement #FrontendEngineering #JavaScript #TypeScript #SoftwareEngineering

🚀 Understanding Node.js Internals: Event Loop & Thread Pool This week, I took a deeper dive into how Node.js actually works behind the scenes — and it completely changed how I think about asynchronous code. 🔹 JavaScript in Node.js runs on a single thread 🔹 Yet it handles multiple tasks efficiently using the Event Loop 🔹 Heavy operations are offloaded to the Thread Pool (via libuv) Some key takeaways: Event Loop manages execution in phases (Timers, I/O, setImmediate, etc.) setTimeout(0) is not truly immediate setImmediate() behaves differently inside vs outside I/O process.nextTick() runs before the event loop even starts Understanding these concepts makes async behavior much more predictable and helps write better backend code. Would love to hear your thoughts or corrections 🙌! Blog Link : https://lnkd.in/gxBA4DeT #JavaScript #WebDev #LearnInPublic #Blog #libuv #EventLoop #ThreadPool #ChaiCode Thanks to Hitesh Choudhary, Piyush Garg, Jay Kadlag, Akash Kadlag for guidance 😊