Node.js Fundamentals: Understanding V8 Engine & Event Loop

I was reading somewhere that APIs are dying and got amused. In an instant I related it to NestJS anatomy. Let's think for a moment about how an API in NestJS actually works. Your controller takes the request, reads the intent, routes to the right service. Clean. Predictable. Now look at what an LLM agent does. Give it a goal — it reads the intent, picks the right tool, calls it in the right order. No controller. No routing logic written by hand. Your @Service, your DB, your business logic — untouched. But the routing brain on top? An agent handles that reasoning itself. MCP and CLI aren't killing REST. They're just making the controller irrelevant. The new backend problem isn't designing good endpoints. It's designing services an agent can navigate without you in the room. Most teams haven't realised that yet. #NestJS #BackendEngineering #LLM #MCP #SoftwareArchitecture #NodeJS #AIAgents #REST #SystemDesign #WebDevelopment

⚡ Ever wondered what really happens when JavaScript runs in the browser? Jason Williams, Senior Software Engineer at Bloomberg LP, explores building JS engines through his work on Boa in Rust, and what it reveals about how JS is parsed, executed, and the hidden complexity of the ECMAScript spec. Don’t miss it at JSNation: https://jsnation.com/

Stop writing messy Service files. 🛑 If your API logic is scattered everywhere, try switching to a Class-based structure. Here is the pattern I use to keep my codebase scalable: 1️⃣ Encapsulation: Keep logic private. 2️⃣ Reusability: Extend base classes for common utilities. 3️⃣ Type Safety: Much easier to type with JSDoc or TypeScript. Swipe to see the structure. 👉 How do you organize your service folders? #CodingTips #JavaScriptDeveloper #SystemDesign #Backend

The Ultimate JS Success Story Abandons JS The tool that made JavaScript enterprise-ready is abandoning JavaScript. Microsoft is rewriting the TypeScript compiler in Go. Why? Pure performance. Node.js hits a hard ceiling on heavy CPU-bound tasks like massive AST parsing. Go’s concurrency model shatters that ceiling. The architectural irony is incredible. We spent a decade proving JavaScript could run anywhere. Now we are finally admitting it shouldn't. I've watched this shift accelerate as Rust took over our build tools with SWC and Turbopack. Now it’s happening to the compiler itself. JavaScript won the UI. Systems languages won the infrastructure. Are you still forcing heavy backend workers through Node?

Most RAG tutorials work perfectly… until you try them in the real world. So I stopped reading and started building. A few weeks (and a lot of debugging) later — here’s what actually broke: → BM25 is in-memory Server restart = index gone No errors. Just silently worse results. → Vector search struggles with exact queries Try searching: “error code E403” or “invoice #INV-2024-001” Embeddings alone won’t save you. → I accidentally added TWO LLM calls in my query pipeline One to answer. One to judge the answer. (Yes… the second one was intentional. Mostly.) That’s when it clicked: You don’t need just RAG. You need Hybrid RAG. So I built one using: Node.js · TypeScript · BullMQ · Chroma · HuggingFace · RRF It’s faster, more reliable, and actually works beyond demos. Full breakdown in the comments 👇 Would love feedback from folks who’ve built real-world RAG systems. #RAG #nodejs #typescript

Just built a web application — a simple document approval web application where users can submit docs, invite reviewers, and make approval decisions on review requests. Built the backend in Go with MySQL as the database, GORM for database access, and Uber's Fx to keep the API modular. The frontend built in React Vite + TypeScript. Also use OpenCode as AI agent tool to handle some repetitive boilerplate codes Check out the project on GitHub: https://lnkd.in/gxrC6W7R

Part 5 of our contract-first series. This time: NestJS. It's had an open issue for spec-first support since 2020 so Yuri Mikhin built a plugin for Hey API, and contributed it upstream. One implements clause and your controllers either match the spec or the build fails: https://lnkd.in/dYERbYEv

Built RepoMap because, reading someone else's codebase was taking too long 🗺️ What it does: Paste any GitHub URL → instantly see the full repo as an interactive mind map Features: File architecture visualized Dependency graph (see what imports what) Expand/collapse folders Live search Private repo support via token Built it with AI assistance mostly for myself. Tired of scrolling through 50 folders trying to understand how a project is structured. Tech: Next.js, React Flow, GitHub REST API Try it free on any public repo: https://lnkd.in/gmzfN9Yd #WebDevelopment #NextJS #JavaScript #BuildInPublic #DeveloperTools

TypeScript 6.0 just came out. And most developers are going to upgrade on Monday morning without thinking. I tested the beta on a Nuxt project in production six weeks ago. Not out of curiosity, because I refuse to say “I don’t know” when a client asks if we should upgrade. TS6 isn’t really a feature release. It’s the last one before the compiler gets rewritten in Go. And that means a lot of things break. Defaults change everywhere: strict mode activated, ES5 deprecated, CommonJS done. Your tsconfig from 3 years ago is going to fail. The easy reflex: google the error, paste the fix, push. Done. But you can also pause for 30 seconds and ask yourself real questions. Do we actually still need CommonJS? Does this ES5 target serve any purpose? Can we finally clean up that legacy config nobody dares touch? When I tested, I found 3 flags we’d never touched. One of them had no effect since we target ES2015+. It was just there. “It works, don’t touch it.” TS6 isn’t an upgrade. It’s an audit of your past decisions. Should you upgrade now? No. Not mid-sprint, not without solid tests. TS7 arrives in a few months, that’s the real rupture. TS6 gives you time. But if your answer is “ignoreDeprecations and we’ll see later”, you don’t get it. You’re just piling up debt. The real question isn’t “how do we pass the build”. It’s “what does this release reveal about our stack”. Have you touched TS6 yet? What broke first?

Oh, Great Masters of Code (and those just passing by)! Gather 'round for the tale of how our valiant developers wrestled with the hydra known as TypeScript 6.0.3, and why apps/microservices/upload now looks like it was chewed up and spat out by Babel. 🤡 The Problem: When TS Thought It Was the Sheriff After we upgraded to TypeScript 6, our API Gateway and upload microservice decided that actually working was beneath them. Webpack, paired with ts-loader, started screaming TS5011 and TS6059 errors, complaining that library files from libs/ weren't sitting neatly under the rootDir. TS 6 suddenly realized the world is bigger than the apps/api folder and had an existential crisis, blocking the build because its narrow worldview couldn't handle external imports. 🛠 "Genius" Attempts (That Failed Miserably): We tried being polite: - Rearranging folders (Flattening src/app). - Begging through tsconfig (rootDir, rootDirs). - Trying to trick it with paths and buildLibsFromSource. The Result: TS 6 just found new reasons to complain. It’s like that toxic ex—no matter what you do, it's never enough. 🔨 The Solution: Surgical Removal of TypeScript (from the Build Pipeline) Eventually, we realized that if ts-loader is going to act like a drama queen, we should just... fire it. In apps/microservices/upload/project.json (and the API too), we pulled this stunt: - Swapped the Compiler: We told Webpack: "Forget tsc, your new best friend is babel." - Added .babelrc: We stuffed @nx/js/babel in there. Now Babel just strips the types without asking annoying questions about project structure. It doesn't give a damn about your rootDir; it just gets the job done. - Muzzled Type Checking: We set typeCheckOptions: false and buildLibsFromSource: false. 🎤 The Verdict (Humiliating, but Honest): We "solved" the TypeScript 6 incompatibility by simply forbidding TypeScript from checking types during the build. Now our upload service builds fast and without backtalk because we replaced the strict teacher with a ruler (tsc) with a relaxed hippie (babel) who says: "Man, I don't care where that file came from, I'm just gonna turn it into JS." P.S. The linter is still grumbling about any in the code, but who cares when the build is green and we're the geniuses of the "lazy fix"? 🥂 Say hi to Babel!