Vivek Yadav’s Post

👀If a useEffect only exists to sync derived data… it might not need to exist at all. Derived values don’t need to be stored. They can be computed. Fewer effects. Cleaner components ✨ #react #frontend #javascript #webdev #softwareengineering

When TypeScript doesn’t believe you; Part 1 - Type Predicates You get data from an API. A user can be admin or a regular user: typeAdmin = { role: "admin"; permissions: string[]; }; typeUser = { role: "user"; email: string; }; typeUserFromApi = Admin | User; Now you want to work with it: functionhandleUser(user: UserFromApi) { if (user.permissions) { user.permissions.push("delete"); // ❌ error } } TypeScript says: “How do I know this is an admin?” “It could be a regular user.” ✅ The fix: Type Predicate (custom type guard) #typescript #frontend #webdevelopment #javascript #tech

#Headline: 🚀 Day 2: Mastering Automation & Dynamic Server Communication in Node.js! Consistency is key, and Day 2 was all about making the development process faster and smarter. Today, I moved beyond static servers to understand how real-time data flow works in a backend environment. Key Learnings Today: ✅ Workflow Automation: Successfully integrated Nodemon. No more manual server restarts! Now, my environment auto-updates as soon as I hit save, significantly boosting my productivity. ⚡ ✅ The Anatomy of a Response: Deep-dived into the res (Response) object. Learned how to set HTTP Status Codes (200 OK) and Content-Type headers to help browsers interpret data correctly. 🌐 ✅ Dynamic Data Injection: Practiced passing JavaScript variables and functions into HTML responses using Template Literals. This is the foundation of building dynamic web applications! 🛠️ ✅ CLI Mastery: Continued my journey with Git commands via Terminal to keep my progress documented and version-controlled. Technical Deep-Dive: Understanding that every request needs a proper res.end() to prevent infinite loading was a simple yet crucial "Aha!" moment today. 📂 You can check out my Day 2 code here: 👉 https://lnkd.in/gdQTt9nC Excited to keep this momentum going into Day 3! Any tips for optimizing Node.js workflows? Let's discuss below! 👇 #NodeJS #BackendDevelopment #Javascript #WebDev #Nodemon #Programming #LearningInPublic #30DaysOfCode #GitHub #SoftwareEngineering #WebDeveloper

⏳ “JavaScript is single-threaded.” I used to hear this everywhere. But then I had one question: If JavaScript is single-threaded… How does async code work? That’s when I learned about the Event Loop. Here’s the simple idea 👇 🧠 JavaScript has: • Call Stack • Web APIs • Callback Queue • Event Loop When async code runs (like setTimeout or fetch): 1️⃣ It moves to Web APIs 2️⃣ Once completed, it goes to the Callback Queue 3️⃣ The Event Loop checks if the call stack is empty 4️⃣ Then pushes it back to execute That’s why: console.log(1) setTimeout(() => console.log(2), 0) console.log(3) Output is: 1 3 2 Understanding this made debugging async bugs much easier. Frameworks don’t hide this. They rely on it. #JavaScript #EventLoop #WebDevelopment #FrontendDeveloper #NodeJS #SheryiansCodingSchool

Day 4 – Node.js Understanding Callbacks Today’s topic: Callbacks in Node.js. A callback is a function passed as an argument to another function. It gets executed after a task completes. Node.js uses callbacks mainly for asynchronous operations such as: • File system operations • Database queries • API requests Callbacks help Node.js follow a non-blocking execution model. Instead of waiting for a task to finish, the function is registered and executed later. Next: Promises and async/await to handle asynchronous code in a cleaner way. #NodeJS #BackendDevelopment #JavaScript #AsyncProgramming #SoftwareEngineering

🚀 How JavaScript Works Behind the Scenes (Short Version) JavaScript looks simple, but internally a lot is happening. • V8 Engine (Chrome & Node.js) It converts JS into machine code and runs it. Uses: Call Stack → Executes synchronous code Heap → Stores objects & memory • Web APIs + Event Loop Async tasks like setTimeout, fetch, and DOM events go to Web APIs. After completion: Promises → Microtask Queue Timers/Events → Callback Queue The Event Loop moves them to the Call Stack when it's empty. • Garbage Collection V8 uses Mark & Sweep to remove unused memory. Poor reference handling can cause memory leaks. Client vs Server Browser → V8 + Web APIs Node.js → V8 + libuv (async I/O, worker threads) Understanding this helps in writing optimized, scalable, and industry-ready JavaScript. #JavaScript #V8 #EventLoop #WebDevelopment Vikas Kumar Pratyush Mishra

People often say “Node.js is single-threaded,” but very few understand why it was designed that way. JavaScript originally ran in the browser, where multiple threads updating the UI at the same time would create race conditions and constant crashes. So the language stayed single-threaded for safety. Node.js simply continued that model and paired it with an asynchronous event loop and a hidden worker-thread pool underneath. That’s why Node handles massive I/O workloads without ever exposing developers to the complexity of locks, semaphores, or thread management. It looks single-threaded, but internally behaves like a controlled multi-threaded system, giving performance without the pain of real multi-threading. #nodejs #javascript #systemdesign #backend #cpp #eventloop

🔥 Scenario-Based Questions (Important for 2-3 YOE) Since you are working on real projects, expect questions like: How did TypeScript improve your React project? How do you type API responses? How do you handle dynamic data types? How do you type Redux state? How do you fix type errors in large projects? 🎯 Most Important Topics to Prepare ✔ Interfaces vs Types ✔ Generics ✔ Utility Types (Partial, Pick, Omit) ✔ Type Narrowing ✔ React with TypeScript ✔ API Response Typing ✔ Strict Mode #ReactJS #TypeScript #JavaScript #FrontendDeveloper #WebDevelopment #Coding #SoftwareEngineering #Interviewquestion

⚡ JavaScript Tip: Cleaner Promise Error Handling Developers often use this trick to catch sync errors in promise chains. ❌ Before Promise.resolve() .then(() => JSON.parse(data)) .then(result => console.log(result)) .catch(err => console.error(err)); ✅ Now with Promise.try() Promise.try(() => JSON.parse(data)) .then(result => console.log(result)) .catch(err => console.error(err)); ✔ Less boilerplate ✔ More readable async flows ✔ Cleaner error handling Sometimes the best language improvements are the smallest ones. Would you start using Promise.try() in your projects? #JavaScript #ESNext #NodeJS #WebDevelopment #CodingTips