React Rerenders: Causes and Optimization Strategies

#One_real_production_lesson_frontend_dev_taught_me: We had a bug in production where an API was getting called twice. At first, it looked like a backend issue. But the backend logs were clean. So I started digging into the frontend 👇 The culprit? 👉 React 18 Strict Mode. In development, React intentionally runs components twice to detect side effects. But our code wasn’t written with that in mind. Here’s what we had: ❌ API call inside "useEffect" without proper safeguards ❌ No cleanup / idempotent logic ❌ Assumption: "useEffect runs only once" Result: Duplicate API calls → inconsistent data → confused users. --- ✅ Fix: - Made API calls idempotent - Added proper checks before firing requests - Avoided unnecessary side effects inside "useEffect" --- 💡 Lesson: Writing code that works is easy. Writing code that works in real-world scenarios is the real skill. React doesn’t cause bugs. Our assumptions do. --- Since then, I always ask: 👉 “What happens if this runs twice?” 👉 “Is this safe in concurrent rendering?” --- Still learning something new every day 🚀 #FrontendDevelopment #ReactJS #JavaScript #CleanCode #WebDevelopment #Debugging

𝐄𝐯𝐞𝐧 𝐚𝐬 𝐚𝐧 𝐞𝐱𝐩𝐞𝐫𝐢𝐞𝐧𝐜𝐞𝐝 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫, 𝐈 𝐬𝐭𝐢𝐥𝐥 𝐬𝐨𝐦𝐞𝐭𝐢𝐦𝐞𝐬 𝐦𝐚𝐤𝐞 𝐬𝐢𝐦𝐩𝐥𝐞 𝐦𝐢𝐬𝐭𝐚𝐤𝐞𝐬. Today React threw: ❌ “Uncaught Error: input is a void element tag and must neither have children nor use dangerouslySetInnerHTML” I checked the code twice and didn’t notice it at first. I had written: <𝑖𝑛𝑝𝑢𝑡>  𝐸𝑛𝑡𝑒𝑟 𝑛𝑎𝑚𝑒 </𝑖𝑛𝑝𝑢𝑡> I wrote it almost automatically… and didn’t even realize. The issue? <input> is a void element in HTML. That means: 1️⃣ No children 2️⃣ No closing tag 3️⃣ Must be self-closing <𝑖𝑛𝑝𝑢𝑡 𝑡𝑦𝑝𝑒="𝑡𝑒𝑥𝑡" /> 💡 Reminder: Experience doesn’t mean you stop making mistakes. It means you understand them faster. Frameworks don’t replace fundamentals. They enforce them. #ReactJS #FrontendEngineering #LearningNeverStops #WebDevelopment

Full-stack TypeScript with tRPC unlocks a level of type safety that most developers overlook — and it changes everything. If you want truly seamless end-to-end type safety, these three tips will sharpen your approach: 1. Define your API types **only once** in your tRPC router. When your backend routes and frontend queries share the same contract, your editor catches mismatches before they become bugs. No more duplicating DTOs or manual sync tasks. 2. Use tRPC’s `inferProcedureOutput` to extract response types dynamically. This avoids over-typing your frontend and keeps your code DRY. For example: ```ts type User = inferProcedureOutput<AppRouter['getUser']>; const user: User = await trpc.getUser.query({ id: '123' }); ``` 3. (Hidden gem) Combine tRPC with Zod schemas for runtime validation *and* type inference. Many devs use Zod only for validation, but it’s a powerhouse for guaranteed type safety in inputs and outputs. This reduces bugs that sneak past TypeScript’s static checks. In my last project, AI-assisted development helped me prototype a tRPC-powered full-stack app in under an hour, maintaining strict types throughout. That kind of speed and confidence? Game changer. Which of these was new to you? How do you maintain type safety in your full-stack projects? #WebDevelopment #TypeScript #Frontend #JavaScript

REACT NOTES — PART 3 (Advanced Concepts) After understanding components and hooks, the next step is learning how React applications scale. This post focuses on concepts that improve architecture and performance in real projects: • Context API and avoiding prop drilling • Sharing data across components with useContext • Memoization in React • React.memo, useMemo, and useCallback • Preventing unnecessary re-renders As React apps grow, managing data flow and rendering efficiently becomes more important than writing components. 📌 Save this if you're revising advanced React concepts. #React #FrontendDeveloper #WebDevelopment #JavaScript #InterviewPrep #LearningInPublic #ReactJS #Consistency

⚛️ Improving React Performance with Lazy Loading As React applications grow, the bundle size can increase significantly. Loading all components at once can slow down the initial page load and impact the user experience. React Lazy Loading helps solve this problem by loading components only when they are needed, instead of including everything in the main JavaScript bundle. With tools like "React.lazy()" and "Suspense", React can split the code and dynamically load components when a user navigates to them. Benefits of React Lazy Loading: • Smaller initial bundle size • Faster page load • Better performance on slower networks • Improved overall user experience Optimizing how and when components load is a key step in building scalable and high-performance React applications. Reference from 👉 Sheryians Coding School #React #WebDevelopment #Frontend #JavaScript #Performance #SoftwareEngineering

React Hooks changed everything. Here's a simple breakdown every developer should know: 🔵 useState Manages local component state. Think of it as your component's memory. 🟢 useEffect Handles side effects — API calls, subscriptions, timers. Runs after every render by default. 🟡 useContext Access global state without prop drilling. Works perfectly with the Context API. 🔴 useRef Access DOM elements directly. Also stores values without triggering re-renders. 🟣 useMemo Memorizes expensive calculations. Only recalculates when dependencies change. 🟠 useCallback Memorizes functions between renders. Prevents unnecessary child re-renders. ⚪ useReducer Like useState but for complex state logic. Think of it as a mini Redux inside your component. Master these 7 hooks and you'll handle 95% of React challenges. 🚀Save this. Share with a dev who needs it. 🔖Which hook confused you the most when you started? 👇 #React #ReactHooks #Frontend #JavaScript #WebDev"

State management in React has evolved a lot. For a long time, Redux was the default choice. But modern tools like Zustand are changing how developers think about global state. So I decided to dive deeper and compare Redux Toolkit vs Zustand from a practical developer’s perspective. In this article I cover: • How Redux Toolkit actually simplifies traditional Redux • Why many developers are switching to Zustand • Differences in boilerplate, performance, and scalability • Code examples to understand both approaches clearly If you're a React developer, choosing the right state management solution can significantly impact how maintainable your application becomes. Read the full article here: https://lnkd.in/dgkJQ997 Would love to know what you prefer using in real projects — Redux Toolkit or Zustand? #React #ReduxToolkit #Zustand #JavaScript #FrontendDevelopment Sharing this on LinkedIn to discuss with fellow developers 🚀

Mastering State Management in React! ⚛️ I recently dove deep into React Hooks, specifically useState and useEffect, to build this functional To-Do List. It’s one thing to understand the syntax, but another to implement: ✅ CRUD Operations: Adding, Editing, and Deleting tasks seamlessly. 💾 Persistence: Using localStorage via useEffect so your data doesn't vanish on refresh. 🔄 Conditional Rendering: Handling UI states for "Edit" vs "Add" modes. Check out the video to see the logic behind the UI! #ReactJS #WebDevelopment #FrontendEngineer #Javascript #ReactHooks #CodingLife #PortfolioProject

A lot of developers get confused between controlled and uncontrolled inputs in React — the difference is small, but it changes everything. 🔹 Controlled Inputs Here, React controls the input using state (useState). Every change goes through React, which makes validation, real-time updates, and data handling much easier. 🔹 Uncontrolled Inputs Here, the DOM manages the input state. You access the value using useRef only when needed, which can be useful in simpler or less interactive scenarios. 📌 The difference is just about who controls the data — React or the DOM. But this small difference impacts how you handle validation, performance, and overall form behavior in real-world applications. Understanding this properly makes form handling much more predictable and scalable. #ReactJS #FrontendDevelopment #JavaScript #MERNStack #SoftwareDevelopment #WebDevelopment #FullStackDeveloper #LearningInPublic #CodingJourney #DevelopersLife

5 React mistakes I see even senior devs make (and how to fix them): 1️⃣ Using useEffect for everything → Not every side effect needs useEffect. Derived state? Just compute it. 2️⃣ Prop drilling 10 levels deep → Context API or Zustand for global state. Period. 3️⃣ Not memoizing expensive calculations → useMemo() exists for a reason. Use it wisely. 4️⃣ Fetching data inside components without cleanup → Always return a cleanup function. Memory leaks are silent killers. 5️⃣ Ignoring React DevTools Profiler → You can't optimize what you can't measure. Which one have you been guilty of? 👇 #ReactJS #JavaScript #FrontendDevelopment #WebDev #MERN