Node.js Internals: Event Loop, Async Behavior & Timers

Day 65/100 – Starting with Node.js 🚀 Learned: What Node.js is and how it allows JavaScript to run outside the browser Basic idea of the Event Loop and how Node handles multiple requests efficiently Introduction to Express and how it simplifies backend development What stood out: Node.js doesn’t work like traditional synchronous systems. Instead of waiting, it handles tasks asynchronously using the event loop, making it fast and scalable. #NodeJS #BackendDevelopment #JavaScript #LearningInPublic #100DaysOfCode

Today’s session by Piyush Garg sir was a deep dive into Node.js Internals 🔍 Instead of just writing code, we explored what actually happens behind the scenes in Node.js. Key things I learned: • How the Event Loop works • The role of libuv in handling async operations • How Node.js manages non-blocking tasks efficiently Understanding these fundamentals makes backend development much clearer. Excited to keep exploring the internals of Node.js! #NodeJS #BackendDevelopment #WebDevelopment #JavaScript #ChaiCode Hitesh Choudhary, Chai Aur Code, Akash Kadlag, Jay Kadlag,

Today Class was on Internals of Node.js! Understood how Node.js runs on a single main thread, uses the event loop to handle async tasks, and a thread pool (default 4 threads) for heavy operations. Also learned how phases like I/O polling, expired callbacks, and setImmediate work behind the scenes. Really interesting to see how Node.js executes code internally. #NodeJS #NodeJSInternals #JavaScript #EventLoop #ChaiCohort26 #Chaicode Hitesh Choudhary Chai Code #piyushgarg Anirudh Jwala Akash Kadlag Jay Kadlag JavaScript

Node.js is dying Most devs think replacing it with Bun is a no-brainer due to its 5x throughput boost. But what they miss is that this shift also means relearning entire ecosystems and toolchains. Can we really afford to ditch the massive Node.js community for a speed bump? . . . . #MERNstack #Nodejs #Bun #JavaScript #DevDebate

Day 2 🚀 It’s working. From idea → to a working CLI that sets up my full stack in one command ⚡ What it does: • Creates frontend/ (Next.js) • Creates backend/ (Express + MongoDB ready) • Sets up basic structure + routes Run once → start coding instantly. Next step: Publishing it as an npm package 📦 Turning a repetitive problem into a real tool feels 🔥 Would you use something like this? #BuildInPublic #JavaScript #NextJS #NodeJS #CLI

🚀 Today I learned something really interesting about the Node.js Event Loop. I always assumed the event loop behaves the same everywhere, but it actually works differently in the Browser vs the Node.js environment. In Node.js, the event loop goes through multiple phases such as: • Timers (Expired Callbacks) • I/O Polling • setImmediate • Close Callbacks Understanding these phases really helped me see how asynchronous operations are scheduled and executed under the hood. It also made me realize how important it is to understand core fundamentals, not just frameworks. The deeper you go into JavaScript, the more fascinating it gets. ⚡ Thanks Piyush Garg and Hitesh Choudhary for such a great explanation. #NodeJS #JavaScript #BackendDevelopment #LearningInPublic #EventLoop

universal-helper-functions is now live on npm! I am excited to share this new utility package for JavaScript and TypeScript developers. What you get: - 14 helper modules - 35 type-check utilities - 30 string casing/manipulation utilities - 0 runtime dependencies Built to be lightweight, practical, and easy to use across Node.js and browser projects. Would love your feedback if you try it. npm: https://lnkd.in/gnpxmHTx   GitHub: https://lnkd.in/gfQHWV8G #javascript #typescript #npm #nodejs #webdevelopment #opensource #developertools

🚀 What I Learned Today: Node.js Internals • Node.js runs JavaScript on a single main thread • Top-level code executes first before the event loop starts • Import statements load during initialization • Event Loop manages asynchronous operations Event Loop Phases: • Timers → setTimeout() / setInterval() • I/O Polling → file system & network operations • Check → setImmediate() (Node.js specific) • Close Callbacks → cleanup tasks • Node.js uses a libuv worker thread pool (default: 4 threads) • Thread pool size can be changed using process.env.UV_THREADPOOL_SIZE https://lnkd.in/gwFG5WVW thank you Piyush Garg sir Hitesh Choudhary sir Akash Kadlag sir #chaiaurcode #NodeJS #JavaScript #Backend #EventLoop

🚀 Understanding Node.js Internals: Event Loop & Thread Pool This week, I took a deeper dive into how Node.js actually works behind the scenes — and it completely changed how I think about asynchronous code. 🔹 JavaScript in Node.js runs on a single thread 🔹 Yet it handles multiple tasks efficiently using the Event Loop 🔹 Heavy operations are offloaded to the Thread Pool (via libuv) Some key takeaways: Event Loop manages execution in phases (Timers, I/O, setImmediate, etc.) setTimeout(0) is not truly immediate setImmediate() behaves differently inside vs outside I/O process.nextTick() runs before the event loop even starts Understanding these concepts makes async behavior much more predictable and helps write better backend code. Would love to hear your thoughts or corrections 🙌! Blog Link : https://lnkd.in/gxBA4DeT #JavaScript #WebDev #LearnInPublic #Blog #libuv #EventLoop #ThreadPool #ChaiCode Thanks to Hitesh Choudhary, Piyush Garg, Jay Kadlag, Akash Kadlag for guidance 😊

I still remember the old npm ritual: install a package → hit type errors → hunt down @types/* → repeat 😄 If you’re returning to JS/TS after some time, you’ll notice a big change… 👉 You don’t need @types as much anymore. So what changed? Over the last few years, the ecosystem quietly evolved: • Most modern libraries now ship with built-in TypeScript types • TypeScript is no longer “optional” — it’s the default • Tooling (Vite, tsup, etc.) makes generating types effortless • Newer runtimes are becoming more TS-friendly In short: 📦 Libraries now come “type-ready” out of the box You’ll still see @types/* for: – Older JS libraries – Node/test environments – Some community-maintained packages But the constant back-and-forth? Mostly gone. #TypeScript #JavaScript #WebDevelopment #NodeJS #DeveloperExperience #CodingLife #SoftwareEngineering