React devs: Stop abusing useEffect

🐛 A small bug wasted 3 hours of my time. I was building a React project. Everything looked correct. The API was working. The component was rendering. There were no errors in the console. But the UI was still not updating. For 3 hours, I kept checking the wrong things. Then I finally noticed the problem. I was directly mutating the state instead of creating a new one. Something as small as this: ❌ state.push(newItem) ✅ setState([...state, newItem]) And suddenly, everything started working. That moment reminded me of something important: In development, the biggest problems are often caused by the smallest mistakes. Since then, whenever something doesn’t work, I try to remember: • Don’t panic • Check the basics first • Read the code slowly • Small details matter Because debugging is not just about fixing bugs. It’s about learning how to think better. 💬 What is one bug that taught you an important lesson? #ReactJS #JavaScript #debugging #webdevelopment #developers #learning #softwareengineering

Deeply nested state updates in React are a silent productivity killer. If you've ever spent 10–15 minutes updating one tiny value inside a nested object you already know the pain. I used to mutate nested state directly — until it started affecting performance, debugging time, and even load time optimizations. Here’s a simple mindset shift that made my frontend code cleaner and easier to scale #React #FrontendDevelopment #ReactJS #JavaScript #useReducer #StateManagement #ReactHooks 

⚠️ Most React developers are using the WRONG hook (and don’t even realize it)… If you're working with React, you've probably used useEffect everywhere… But did you know React also gives you useLayoutEffect - and using the wrong one can cause: ❌ UI flickering ❌ Layout glitches ❌ Unexpected behavior Here’s the simplest way to understand it: 👉 useEffect runs after the browser paints 👉 useLayoutEffect runs before the browser paints That’s it. But this tiny difference changes everything. 💡 Use useEffect for: API calls Logging Subscriptions 💡 Use useLayoutEffect for: Measuring DOM elements Updating layout before paint Avoiding visual flicker ⚠️ Pro tip: Don’t overuse useLayoutEffect — it blocks rendering and can hurt performance. I’ve broken it down with examples in the slides 👇 #React #Frontend #JavaScript #WebDevelopment #Programming #SoftwareEngineering

🚨 Most React developers overcomplicate state management After working on multiple projects, I noticed a pattern: Developers jump into tools like Redux, Zustand, or RTK Query too early. But the truth is 👇 👉 70% of your state can be handled with just useState + useReducer Here’s what actually matters: ✅ Keep state close to where it’s used ✅ Avoid global state unless absolutely necessary ✅ Split components instead of adding more logic ✅ Derive state instead of duplicating it Simple example Instead of this: global store multiple selectors unnecessary re-renders You can often do: 👉 local state + props 👉 or a small custom hook 💡 The real skill in React is not adding tools it’s knowing when NOT to use them Curious - what’s the most overused React tool in your opinion? #react #reactnative #frontend #javascript #webdevelopment #programming #softwareengineering #reactjs #cleanCode #developer

react 19 has a new use() api and it breaks one of the oldest rules in react hooks must be called at the top level. always. no conditions, no loops. use() doesn't care. you can call it inside if statements, loops, conditionals - things that were never allowed before. it does two things: - reads a promise (integrates with suspense automatically) - reads context (like useContext, but more flexible) function UserCard({ userPromise }) { const user = use(userPromise); // suspends until resolved return <p>{user.name}</p>; } the catch? create your promises in server components and pass them down - not inside the client component itself, or you'll get an infinite loop on every re-render. it's a small api with a big mental shift. react is clearly moving toward a world where async is first-class - not something you bolt on with useEffect + useState + loading flags. #react #react19 #frontend #javascript #webdev

🧠 React Doesn’t Update State Immediately (Even Inside the Same Function) Most people know state is async. But here’s the part many don’t realize 👇 Example const [count, setCount] = useState(0); function handleClick() { setCount(count + 1); if (count === 0) { console.log("Still zero?"); } } You click the button. Expected: count = 1 But inside that function… 👉 count is still 0 🔍 Why? Because React doesn’t update state inside the current render cycle. It schedules the update and re-renders later. 🧠 The tricky part Even this won’t work: setCount(count + 1); setCount(count + 1); 👉 Final result = +1, not +2 ✅ Correct way setCount(prev => prev + 1); setCount(prev => prev + 1); Now React uses the latest value. 🎯 The Real Insight State inside a function is a snapshot, not a live value. 💥 Why this matters This causes: Unexpected conditions Wrong calculations Confusing bugs #ReactJS #FrontendDevelopment #JavaScript #ReactHooks #WebDevelopment #CodingTips #LearningInPublic

🚀 Day 967 of #1000DaysOfCode ✨ useEffect Hook in React (Explained Simply) `useEffect` is one of the most powerful hooks in React — but also one of the most misused. In today’s post, I’ve explained the `useEffect` hook in a simple and practical way, so you can understand how and when to use it correctly. From handling API calls to managing subscriptions and syncing data, `useEffect` helps you deal with side effects in your components. The tricky part is understanding dependencies — which often leads to bugs like infinite loops or missed updates. I’ve also covered common mistakes developers make and how to avoid them in real-world applications. If you’re working with React, mastering `useEffect` will make your code much cleaner and more predictable. 👇 What’s the most confusing part of `useEffect` for you — dependencies or execution timing? #Day967 #learningoftheday #1000daysofcodingchallenge #FrontendDevelopment #WebDevelopment #JavaScript #React #CodingCommunity #ReactJS

https://lnkd.in/dhXuQdTD — I used to think a Length Converter was the "Hello World" of apps. As a Senior Frontend Engineer working with TypeScript, I quickly realized that "simple" tools are where the devil is in the details. Building this for my platform, calculator-all.com, taught me a hard lesson about floating-point math and user trust. 📏 I was using React 19 and Tailwind CSS for the UI, keeping things snappy and responsive. ⚡ But a few users pointed out tiny precision errors when converting between obscure units. I had to dive deep into decimal logic to ensure a carpenter and a physicist could both trust the output. 💻 I used Cursor to iterate through edge cases and Vitest to write a suite of tests for over 20 different units. 🤖 Running everything on Bun and Vite made the development cycle incredibly fast, but the real work was in the logic. 🚀 I even had to account for how different locales format their numbers—something many basic tutorials skip. 🛠️ It’s funny how the tools we take for granted often require the most care behind the scenes. ✨ What’s the most "basic" feature you've built that turned out to be surprisingly complex? 📐 #LengthConverter #FrontendEngineer #TypeScript #ReactJS #WebDevelopment #SoftwareEngineering #Bun #Vite #TailwindCSS #React19 #Testing #Coding #JavaScript #UnitTesting #CalculatorAll

most React developers have too many useEffects. i did too. until i read this rule and couldn't unsee it: if you're using useEffect to sync state with another state you don't need useEffect. here's what i mean. (the pattern 1 .. i see everywhere) but pattern 2 give same result . no effect. no extra render cycle. useEffect is for syncing React with something outside React. - fetching data from an API - setting up a subscription - manually touching the DOM not for calculating values you could just... calculate. every unnecessary useEffect is a hidden render cycle your users pay for. before you write useEffect ask one question: am i syncing with something outside React, or am i just doing math? if it's math delete the effect. #reactjs #typescript #webdevelopment #buildinpublic #javascript

Most developers think the key prop in React is just for lists. But one small mistake with keys can silently destroy your frontend performance and increase load time without you realizing it. I’ve seen apps where random keys caused full component remounts on every render — and debugging that was painful. If you're using Math.random() or changing keys unnecessarily this post might save you hours of debugging. #react #frontend #reactjs #javascript #webdevelopment #frontenddeveloper #softwareengineering #codingtips