Mastering React: From Novice to Expert in 3 Years

React is unidirectional. Data flows down. If you’ve spent any time in React, you know the drill, parents talk to children via props. It’s predictable, and it’s why the library scales. But it leads to the inevitable question, How does the child talk back? It’s not a "reverse prop" or some hidden magic. It’s actually a classic JavaScript pattern. While data flows down, functions are first-class citizens. To let a child communicate, the parent defines a "handler" function and passes it down as a prop. The child doesn't send data up in the traditional sense, it simply executes the function it was given. This is the essence of lifting state up. The parent keeps the "source of truth," and the child remains reusable, only triggering the parent’s logic when an event occurs. Of course, once you’re passing functions down five levels deep, you’re in prop drilling hell. That’s usually the signal to reach for the Context API or a state manager like Zustand to keep your components clean. Are you - context API purist? - prefer a dedicated state manager for handling these flows? #ReactJS #WebDevelopment #SoftwareEngineering #Frontend #Javascript

React Re-rendering Is NOT What You Think… When I started React, I thought: “State changes → Component re-renders → Done” Simple… right? But I was completely WRONG Truth: React doesn’t just re-render that one variable It re-renders the ENTIRE component Example: const [count, setCount] = useState(0); console.log("Component Rendered"); Every click → Whole component runs again All functions re-created All calculations re-execute The Mistake I Made: I was doing heavy work inside components like: const filteredData = data.filter(...) So every render → Expensive calculations again Performance drop The Fix (Game Changer): useMemo() const filteredData = useMemo(() => { return data.filter(...) }, [data]); -----Now it only runs when needed Another Hidden Issue: Functions inside components const handleClick = () => {} Re-created on EVERY render Fix? useCallback() Golden Rule: If something is: Expensive → useMemo Function passed to child → useCallback My Learning: React is not about writing code It’s about controlling re-renders What about you? Did you know your whole component re-renders every time? Devendra Dhote Daneshwar Verma Ritik Rajput #reactjs #javascript #webdevelopment #frontend #performance #coding #reactdeveloper #learninpublic

✨React is no longer just a library… it’s an entire ecosystem. There was a time when learning React meant understanding components, props, and state. Today? That’s just the beginning. ⸻ 💡 Modern React development is about choosing the right tools from its ecosystem: ⚡ Next.js — For production-ready apps SSR, routing, performance — all handled seamlessly. 🧠 State Management (Redux / Zustand) — Manage complex state with clarity and scalability. 📡 React Query / TanStack Query — Fetching, caching, syncing server data — made simple. ⸻ ⚠️ But here’s where many developers get stuck: Trying to learn everything at once. ⸻ 🔥 The truth is: You don’t need every tool. You need the right tool for your use case. Because: ✔ Over-engineering slows you down ✔ Simplicity scales better ✔ Clarity beats complexity ⸻ 💭 A better approach: Start with core React → Add tools as problems grow → Learn by building real projects ⸻ ⚡ Remember: Great developers don’t just know tools… They know when NOT to use them. ⸻ 💬 Question: What’s your go-to React library right now — and why? ⸻ 📌 Save this post if you’re exploring the React ecosystem. #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #NextJS #Redux #Zustand #ReactQuery #Programming #Developers #SoftwareEngineering #TechStack #LearnToCode #BuildInPublic

🚀 Day-23 — Revisiting React Fundamentals Today I revised important React.js concepts and focused on organizing things in a better way. I went through: • Folder Structure — organizing files for scalability Example: src/ ├── components/ ├── hooks/ ├── redux/ ├── pages/ • Components — reusable UI blocks Example: function Button(){ return <button>Click</button> } • Hooks — managing state & lifecycle Example: const [count, setCount] = useState(0) • Redux Toolkit — global state management Example: const counterSlice = createSlice({ name: "counter", initialState: {value: 0}, reducers: { increment: state => { state.value++ } } }) This revision helped me understand how to structure projects better and write cleaner code. Not a heavy coding day, but important for strong fundamentals. Ankur Prajapati Satwik Raj #ReactJS #FrontendDevelopment #ReduxToolkit #WebDevelopment #LearningInPublic #BuildInPublic

🚀 Day 12 — Understanding useEffect in React Today I learned about one of the most important React hooks — useEffect. The useEffect hook is used to handle side effects in React components. Examples of side effects: • API calls • Data fetching • Event listeners • Timers • DOM updates Basic Syntax: useEffect(() => { // side effect code }, []) Important Points I learned: • useEffect runs after component renders • Empty dependency array → runs only once • With dependency → runs when value changes • No dependency → runs on every render Example: useEffect(() => { fetchUsers(); }, []); This hook is very useful when working with APIs and dynamic data. Still learning and applying this in my projects. #ReactJS #FrontendDevelopment #MERNStack #LearningInPublic

By default, React is fast. But as data grows, unnecessary re-renders quietly kill performance. Today I learned two hooks that every serious React developer needs to know: 🗒️ useMemo — A cache for heavy calculations. Instead of re-running expensive logic on every render, React stores the result and reuses it. Think of it like a sticky note your genius friend writes so they don't have to solve the same problem twice. 🔗 useCallback — Stabilizes your functions. In JS, functions are objects — so a "new" one gets created on every render. This hook keeps the reference the same, stopping child components from re-rendering for no reason. The senior wisdom I picked up today? Don't over-optimize. These hooks cost memory. Only reach for them when you actually see a lag — not before. Understanding when to optimize is what separates professional developers from the rest. Tomorrow: I'm building my own tools with Custom React Hooks! 👀 Question for you: Do you optimize as you go, or wait until something feels slow? Drop your strategy below 👇 #CodeWithWajid #ReactJS #WebDevelopment #100DaysOfCode #LearningToCode #BuildingInPublic #ReactOptimization #WebPerf

Exploring NestJS on Day 3 Have you ever wondered what happens when a NestJS application starts? Most developers simply type `npm run start` and move on, but there's a detailed lifecycle that runs every time, and understanding it can save hours of debugging. Here’s the full bootstrap() lifecycle, step by step: 1. Node.js executes main.ts → bootstrap() is called. 2. NestFactory.create(AppModule) builds your application instance. 3. Module graph construction — Nest recursively scans all imports, providers, and controllers before instantiating any of them. 4. IoC container setup — dependencies are resolved in the correct order. 5. Provider instantiation — services, guards, and interceptors are created and wired together. 6. Controller instantiation — routes are registered with the HTTP adapter (Express or Fastify). 7. onModuleInit() hooks fire — each module gets a chance to run async setup. 8. onApplicationBootstrap() hooks fire — everything is initialized. 9. app.listen(3000) — only now does the port open. The key insight here is that Nest scans the entire module graph before instantiating anything. This approach helps catch startup-time errors early and clearly surfaces circular dependency issues, rather than encountering them in the middle of a request. Additionally, this is why bootstrap() is async. If your database connection inside onModuleInit() returns a Promise, Nest waits for it before opening the port, ensuring no half-ready servers. Understanding this lifecycle can make a significant difference when diagnosing startup issues. What part of NestJS would you like me to break down next? Feel free to share in the comments. Also visit on https://lnkd.in/duz59H8w #NestJS #NodeJS #TypeScript #BackendDevelopment #SoftwareEngineering #WebDevelopment

⚛️ “React Hooks are confusing…” — I thought the same at first 😅 When I saw useState and useEffect for the first time,I honestly felt like… 👉 “Why is this so complicated for something so basic?” 🤯 But here’s the truth 👇 Once it clicks, React becomes 10x easier and more powerful. Let me simplify it for you 👇 🧠 What are React Hooks (in simple terms)? 👉 Hooks = a way to give your components “superpowers” -->Store data -->Run logic -->React to changes …without writing messy class components 🙌 🔥 1. useState → Remember things const [count, setCount] = useState(0); 👉 Think: “Hey React, remember this value and update it when I tell you” Example: Counter, form inputs, toggles ⚡ 2. useEffect → Do something when things change useEffect(() => { console.log("Component mounted"); }, []); 👉 Think: “Run this code when something happens” Example : Fetch API data Run code on page load Update UI dynamically 🔁 Why developers love Hooks? ✨ Less code ✨ Cleaner logic ✨ Easier to reuse ✨ No more confusing lifecycle methods 🎯 Real-world example : 👉 You click a button → count updates instantly 👉 You open a page → data loads automatically That’s Hooks doing their magic ⚡ 🚀 My turning point : The day I understood Hooks…I stopped struggling with React and started enjoying it. 💬 Let’s be honest 👇 When you first learned React Hooks, What you felt : 😅 Confused 🤯 Overwhelmed 🔥 “This is actually cool!” Drop your experience below—I’d love to hear your journey! #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #FullStackDeveloper #Developers #CodingJourney

Stop overusing useEffect: 3 patterns for cleaner React code in 2026! While useEffect is one of the most powerful hooks in React, it’s also the most misused. Many developers use it to sync state, leading to unnecessary re-renders and "spaghetti code." In my recent projects, I’ve been focusing on writing more predictable components by following these 3 patterns: 1) You might not need an effect for data transformation If you can calculate something from existing props or state, do it during rendering. - Don't: Use an effect to update a filteredList state when items change. - Do: Use useMemo or just a plain variable during render. It’s faster and simpler. 2) Action handlers over effects If a state change is triggered by a specific user event (like a button click), put that logic in the event handler, not in a useEffect watching the state. It makes the data flow much easier to trace. 3) Lifting State Up vs. Context API Don’t jump straight to Context for everything. Start by lifting state up to the nearest common ancestor. Only move to Context or state management libraries when the prop-drilling actually hurts scalability. The goal? Leaner components, better performance, and easier debugging. What’s a React "bad habit" you’ve recently broken? Let’s share some clean code tips below👇 #ReactJS #TypeScript #WebDevelopment #SoftwareArchitecture #CleanCode #FrontendEngineering #TorontoTech #MERN

Using index as a key is dangerous Every React developer has written this at least once. items.map((item, index) => (  <li key={index}>{item}</li> )) Looks fine. Works fine. But it isn't This is Post 5 of the series: 𝗥𝗲𝗮𝗰𝘁 𝗨𝗻𝗱𝗲𝗿 𝘁𝗵𝗲 𝗛𝗼𝗼𝗱 Where I explain what React is actually doing behind the scenes. Here's what actually happens when you use index as key: You delete one item from a list. React doesn't know which item was removed. It just looks at positions. So it re-renders everything from that index downward. Input states get mismatched. Animations break. Bugs appear that you can't even reproduce consistently. And... No error. Just... wrong behavior. 🔑 Here's what React actually needs: A key isn't just something unique. It needs to be stable, unique, AND tied to the data — not the position. ❌ key={index} → breaks on delete, sort, filter  ❌ key={Math.random()} → new key every render = React destroys and recreates the node  ✅ key={item.id} → stable, reliable, React knows exactly who is who The rule is simple: If your list can ever be reordered, filtered, or deleted from... index as key will silently break your UI. Use your data's ID.  If it doesn't have one, generate it at creation — not during render. const newItem = { id: crypto.randomUUID(),   name: "New Task" } One tiny prop.  Massive impact on how React tracks your entire list. In Post 6 of React Under the Hood: What Happens When You Call setState Follow Farhaan Shaikh if you want to understand react more deeply. 👉 Read the previous post - Understanding diffing algorithm: https://lnkd.in/dzW3NP_V #SoftwareEngineering #ReactJS #WebDevelopment #JavaScript #FrontendDevelopment #BuildInPublic #LearnInPublic #ReactUnderTheHood