React useCallback Misuse: When to Use and When to Avoid

Most React developers think components re-render randomly. They don’t. React actually follows a Depth-First Traversal strategy — and once I understood this, a lot of React’s "weird" behavior suddenly started making sense. 👇 When React updates UI, it doesn't jump around the component tree. It dives deep first — parent → child → child — until it reaches the leaf node. Only then does it backtrack and move to the next sibling. Here’s how React traverses the tree: 🔹 Start from the Root React begins from the root — the top of your component tree. 🔹 Go Deep (Child by Child) It keeps moving downward — first child → next child → until the deepest node. 🔹 Backtrack & Move to Sibling Once React hits a leaf, it goes back to the parent, checks for siblings, and repeats. Now here’s why this matters: ⚡ Fast & Predictable React walks the tree in O(n) — touching each node only once. 🧠 Smart Diffing • If element types change (div → span), React replaces the subtree • For lists, keys help React reuse and reorder nodes efficiently Now the interesting part 👇 This traversal existed even before React Fiber (pre-React 16). But earlier, reconciliation was all-or-nothing. Large component trees could block the main thread and hurt performance. With React 16 (Fiber), traversal became: ⏸️ Interruptible React can pause rendering to handle high-priority updates (like user input) 🔄 Incremental It resumes from where it left off — instead of restarting everything So yes, Depth-First Traversal was always there. React Fiber just made it work with time, not against it. I recently started digging deeper into React internals, and honestly, it’s changing how I structure components and debug performance issues. If you're also exploring React beyond hooks and state — we're probably like-minded. Let’s connect and learn together 🚀 #React #ReactJS #Frontend #WebDevelopment #JavaScript #ReactFiber #SoftwareEngineering #FrontendDevelopment #ReactInternals

Software Engineers reject hookup culture. Because it has: No labels. No rules. No commitment. They already have something that gives them all three. React Hooks. Labels. ✅ Rules. ✅ Commitment. ✅ Try to be casual with it And it'll crash your entire app. This is Post 7 of the series: 𝗥𝗲𝗮𝗰𝘁 𝗨𝗻𝗱𝗲𝗿 𝘁𝗵𝗲 𝗛𝗼𝗼𝗱 Where I explain what React is actually doing behind the scenes. Here's what's actually happening👇 React doesn't track your hooks by name. It tracks them by position. Every render, React walks an internal array. Index by index. Like a strict attendance register. Hook 1 → slot [0] ✅ Hook 2 → slot [1] ✅ Hook 3 → slot [2] ✅ That's the reason when you try to put a hook in an if statement, it gives you an error. function App({ isLoggedIn }) { const [name, setName] = 𝘂𝘀𝗲𝗦𝘁𝗮𝘁𝗲("") // index 0 if (isLoggedIn) { 𝘂𝘀𝗲𝗘𝗳𝗳𝗲𝗰𝘁(() => { ... }) // index 1 (sometimes! as isLoggedIn can be true or false) } const [age, setAge] = 𝘂𝘀𝗲𝗦𝘁𝗮𝘁𝗲(𝟬) // index 1 or 2 ?? } Because: Condition true → all 3 hooks run → slots filled correctly ✅ Condition false → Hook 2 is skipped → React reads age state where it expected useEffect ❌ Your app doesn't just break. It breaks wrong. Wrong values. Wrong renders. Wrong everything. This isn't a bug in React. This IS React. Each component has a Fiber node. That Fiber stores a linked list of hook states. React walks it in order... Every render, no exceptions. The rules of hooks aren't random. They exist because hooks are just an indexed array. Arrays don't care about your variable names. They only care about position. So next time someone asks why hooks have rules It's not React being dramatic. It's React being consistent. Follow Farhaan Shaikh if you want to understand React more deeply. 👉 Read the previous post: How useState works: https://lnkd.in/d7TvJb-W #ReactJS #JavaScript #WebDevelopment #FrontendDevelopment #BuildInPublic #ReactHooks #LearnInPublic #FrontendTips #WebDev #React

⚡ A Simple React Optimization: Using React.memo While building React applications, one thing that can impact performance is unnecessary component re-renders. Sometimes a component re-renders even when its props haven’t changed. This is where React.memo can help. 🔹 What is React.memo? React.memo is a higher-order component that memoizes a component. It prevents re-rendering if the component’s props remain the same. Example 👇 const UserCard = React.memo(({ name }) => { return {name}; }); Now UserCard will only re-render when the name prop actually changes. 🔹 When should you use it? ✅ Components that receive the same props frequently ✅ Pure UI components ✅ Components inside large lists 🔹 When NOT to use it ⚠️ Very small components ⚠️ Components that always receive new props ⚠️ Without measuring performance impact 💡 One thing I’ve learned while working with React: Optimization should always be intentional and measured. Tools like React DevTools Profiler can help identify components that are re-rendering unnecessarily. Curious to hear from other developers 👇 Do you regularly use React.memo, or do you optimize only when performance issues appear? #reactjs #frontenddevelopment #javascript #webdevelopment #reactperformance #softwareengineering #coding

🚀 Building with React: Lessons from Real Projects. Working with React has taught me that building modern applications is not just about designing interfaces it’s about managing data flow, scalability, and performance. Through hands-on experience with React, Redux, and API integration, I’ve learned the importance of: ✔ Creating reusable and modular components ✔ Managing application state efficiently with Redux ✔ Handling API calls and asynchronous data effectively ✔ Maintaining clean and scalable project structures These practices not only improve the performance of an application but also make it easier for teams to collaborate and maintain the codebase. Frontend development continues to evolve rapidly, and it’s exciting to keep learning and building solutions that create real impact. #ReactJS #Redux #FrontendDevelopment #JavaScript #SoftwareEngineering

Why React Apps Feel So Fast (Hint: It’s NOT the DOM) When I first started learning React, I thought: “It directly updates the DOM efficiently.” But that’s not the real magic. The real hero? → Virtual DOM Here’s how it works: 1️⃣ React creates a Virtual DOM (a lightweight copy of the real DOM) 2️⃣ When state changes, React creates a new Virtual DOM 3️⃣ It compares the old vs new (this is called diffing) 4️⃣ Only the changed parts are updated in the real DOM (reconciliation) Result: Instead of reloading the entire page, React updates ONLY what changed. Think of it like this: Imagine updating a document: Rewrite the whole file Just edit the changed lines React chooses the second approach Why this matters: • Better performance • Smoother UI updates • Scalable applications One thing I realized: React is not “fast because of DOM” It’s fast because it avoids unnecessary DOM work If you're learning frontend, understanding this concept changes how you think about UI updates. What was your “aha moment” while learning React? #React #WebDevelopment #Frontend #JavaScript #CodingJourney

🚀 From Zero to React Master — My Complete Roadmap I stopped learning React randomly… and started following a structured roadmap. Here’s the exact path I’m using to go from basics to expert level 👇 🔹 Phase 1 — Foundation JSX, Components, Props, useState, Event Handling, Forms, Lists & Conditional Rendering 👉 Goal: Build strong core understanding 🔹 Phase 2 — Core Hooks useEffect, useRef, useContext, useReducer, useMemo, useCallback 👉 Goal: Master how React actually works under the hood 🔹 Phase 3 — Advanced React Lifecycle, Performance Optimization, Code Splitting, Portals, HOC, Virtual DOM 👉 Goal: Think like a senior developer 🔹 Phase 4 — Expert Level State Architecture, Server Components, Testing, SSR, Accessibility 👉 Goal: Production-level expertise 🔹 Phase 5 — Ecosystem & Real Projects React Router, Redux Toolkit, React Query, Next.js, Auth, Real Projects 👉 Goal: Become job-ready 🚀 💡 Key Lesson: Random tutorials don’t make you a developer. Structured learning + real projects = Real growth I’m currently following this roadmap daily and building projects alongside. If you're learning React, this might help you stay on track 💪 #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #ReactDeveloper #LearnToCode #CodingJourney #SoftwareDeveloper #100DaysOfCode #ReactLearning #NextJS #Redux #ReactQuery #Developers #TechCareer #Programming #CodeNewbie #SelfTaughtDeveloper #FullStackDeveloper #TechGrowth

🚀 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

A small mistake I used to make in React: Re-rendering components more than needed. At first, I didn’t think much about it — everything was “working fine.” But as components grew, I started noticing: • Unnecessary re-renders • Slower UI updates • Harder debugging What helped me improve: • Using React.memo for pure components • Avoiding inline functions/objects where not needed • Proper use of useCallback and useMemo • Avoiding unnecessary useEffect usage • Managing dependency arrays correctly • Keeping state as minimal as possible Big learning: 👉 Just because it works doesn’t mean it’s efficient. Performance issues often come from small habits, not big mistakes. Still learning, but being mindful of re-renders and side effects has made a noticeable difference. What’s one React mistake you fixed that improved performance? #reactjs #javascript #webdevelopment #frontend #fullstackdeveloper

Most beginners think React / Next.js is just about writing code… but the real game starts when you understand components. At this stage (Month 5–6), everything changes. You stop building random pages… and start building reusable systems. A button is no longer just a button. It becomes a component you can use anywhere. A simple UI turns into a structured application powered by props, state, and hooks. This is where you learn: ✔ How to break complex UI into small pieces ✔ How to manage data with state & props ✔ How to build dynamic, fast, and scalable apps ✔ How Next.js takes it further with performance (SSR & CSR) This phase separates beginners from real developers. Because real developers don’t just write code… they build smart, reusable, and scalable architectures. 👉 Master components, and you unlock the real power of frontend development. #ReactJS #NextJS #FrontendDevelopment #WebDevelopment #CodingJourney #JavaScript #LearnToCode #DevelopersLife #UIEngineering #TechSkills

⚛️ Why I Prefer React.js for Frontend Development While learning frontend development, I explored different approaches—but React stood out. Here’s why: ✅ Component-based architecture → Makes code reusable and clean ✅ Fast performance → Thanks to Virtual DOM ✅ Strong ecosystem → Huge community + libraries ✅ Easy to scale → Perfect for large applications 🚀 As someone building full-stack projects, React helps me structure UI efficiently. Still learning and exploring more every day! What frontend framework do you use? 👇 #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #MERN