React Fiber: Async Scheduling Like an OS

Today I spent the whole day exploring how frontend projects are actually structured at an industry level. Earlier when I was building projects in React, my focus was mostly on just making the UI work. But today a question came to my mind how do real companies structure large React applications so that they remain scalable and maintainable? So I started digging deeper and learned about the 4-layer architecture approach in React and how proper industry-level folder structures are designed. Instead of keeping everything randomly in components, the project is divided into clear layers like: - API / services layer - state management / logic layer - UI components - pages / features This separation makes the codebase much cleaner, easier to scale, and much easier for teams to work together. To understand it properly, I didn't just read about it I practiced it 2–3 times by implementing an authentication API flow using the same architecture. Spending the entire day experimenting with this really changed the way I think about frontend development. It’s not just about making things work, it’s about building systems that can grow. Always learning. Always improving. #React #FrontendDevelopment #WebDevelopment #LearningInPublic

React 19 Scheduling & Lanes — The Hidden Engine Behind Your UI Most developers think React updates instantly. It doesn’t. React schedules updates. And it uses something called “Lanes.” 🧠 What is Scheduling in React? When you call: setState(...) React doesn’t immediately update the DOM. Instead it: 1️⃣ Assigns the update a priority 2️⃣ Puts it into a lane 3️⃣ Schedules when it should run 4️⃣ Interrupts or continues work intelligently This is powered by the Concurrent Rendering architecture. 🎯 So What Are Lanes? Think of lanes like priority highways. Each update goes into a specific lane based on importance. Typing input--> High Button click--> High Transition updates--> Medium Background updates--> Low React decides: 👉 What should run first 👉 What can wait 👉 What can be interrupted ⚡ Example with startTransition startTransition(() => { setFilteredData(heavyComputation()); }); (To read more about transition - https://lnkd.in/g_7dF-y9 ) This update goes into a transition lane (lower priority). So: ✔ Typing stays responsive ✔ UI doesn’t freeze ✔ Heavy render runs in background That’s scheduling at work. 🚀 Why React 19 Feels Smarter React 18 introduced concurrent rendering. React 19 refines scheduling, improves async handling, and makes transitions + suspense work more predictably. Lanes allow: ✔ Interruptible rendering ✔ Better CPU time slicing ✔ Prioritized updates ✔ Smoother UX React is no longer: “Render everything immediately.” It is now: “Render what matters first.” 💎 The Big Insight If your UI lags… It’s not just about memoization. It’s about update priority. And lanes are controlling it behind the scenes. React isn’t just a UI library. It’s a scheduler. 💬 Did you know React assigns priorities internally using lanes? Want a deeper dive into how Fiber + lanes work together? Let’s discuss 👇 #ReactJS #React19 #FrontendDevelopment #JavaScript #ConcurrentRendering #WebPerformance #SoftwareEngineering #LearnInPublic 🚀

Building a Next.js platform is one thing. Building one that performs reliably at scale is real engineering. A Frontend can look excellent when 10 people are using it. The real challenge begins when that same platform is being used by hundreds or thousands of users across different devices, network conditions, and hardware capabilities. This is where performance stops being a cosmetic concern and becomes an engineering discipline. A high-performing Next.js platform is not defined only by how fast it feels on a powerful laptop with a stable connection. It must also remain responsive and usable for someone on a low-RAM mobile device, an older desktop, or a slower network. That requires much more than simply shipping features. It requires deliberate decisions around: -rendering strategy -server and client component boundaries -caching and revalidation -bundle size control -asset optimization -API efficiency -memory usage -loading priorities -observability in production At a small scale, many poor decisions go unnoticed. At a larger scale, they become expensive: -oversized JavaScript bundles -excessive client-side rendering -unnecessary re-renders -unoptimized images and fonts -repeated API requests -weak caching strategy -third-party script overhead -degraded Core Web Vitals A strong Next.js platform should be designed to handle both traffic growth and device diversity. That means: sending less JavaScript to the browser using Server Components where appropriate lazy-loading non-critical features optimizing images, fonts, and scripts reducing request waterfalls designing efficient data-fetching patterns testing under constrained CPU, memory, and network conditions monitoring real user performance in production Performance is not just about making an application fast for ideal users. It is about making it reliable for real users. And that is exactly where engineering stands apart from “vibe coding.” Because scalable frontend performance is not achieved through guesswork or aesthetics alone. It comes from architecture, trade-off analysis, profiling, measurement, and continuous refinement. Anyone can build an interface that looks good in a demo. An engineer builds a platform that performs in production. #Nextjs #FrontendEngineering #WebPerformance #SoftwareEngineering #ScalableSystems #ReactJS #PerformanceOptimization #SystemDesign #CoreWebVitals #EngineeringLeadership

Most beginners think Frontend = UI + Functions + Performance. That’s a trap. ⚠️ The real difference between a junior developer and a professional frontend engineer is in the small invisible details users don’t notice… until they’re missing. Here are 10 tiny frontend things you should NEVER ignore: 1️⃣ Proper Error Handling Don’t just console.log(error). Show meaningful, human-readable messages. 2️⃣ Smart Notifications Success, warning, retry states — users need feedback for every action. 3️⃣ Loading States (Everywhere) Buttons, tables, API calls. No dead clicks. Ever. 4️⃣ Empty States “No data found” is better than a broken layout. 5️⃣ Edge Case Handling What if the API returns null? 0? Huge data? Slow response? 6️⃣ Form Validation (Client + Server) Real-time validation builds trust. 7️⃣ Accessibility (a11y) Keyboard navigation. ARIA labels. Proper contrast. If everyone can’t use it — it’s not done. 8️⃣ Micro-interactions Hover effects, transitions, subtle animations. Small polish = premium feel. 9️⃣ Performance Optimization Lazy loading, memoization, code splitting. Fast apps win users. 🔟 Consistent UX Patterns Buttons behave the same everywhere. Don’t confuse users with creativity. The truth is: ✨ Beautiful UI gets attention. ⚙️ Clean logic makes it work. 🧠 But thoughtful details make users stay. Frontend isn’t about making it look good. It’s about making it feel right. What’s one frontend mistake you learned the hard way? #FrontendDevelopment #WebDevelopment #UIUX #JavaScript #React #Programming #SoftwareEngineering

𝙃𝙤𝙩 𝙩𝙖𝙠𝙚: #𝙈𝙞𝙘𝙧𝙤𝙁𝙧𝙤𝙣𝙩𝙚𝙣𝙙𝙨 𝙖𝙧𝙚𝙣’𝙩 𝙧𝙚𝙫𝙤𝙡𝙪𝙩𝙞𝙤𝙣𝙖𝙧𝙮 𝙖𝙧𝙘𝙝𝙞𝙩𝙚𝙘𝙩𝙪𝙧𝙚. 𝙏𝙝𝙚𝙮’𝙧𝙚 𝙤𝙧𝙜𝙖𝙣𝙞𝙯𝙖𝙩𝙞𝙤𝙣𝙖𝙡 𝙩𝙝𝙚𝙧𝙖𝙥𝙮 𝙙𝙞𝙨𝙜𝙪𝙞𝙨𝙚𝙙 𝙖𝙨 𝙘𝙤𝙙𝙚. I just published a piece that might annoy a few people in #FrontendEngineering. We keep acting like #ModuleFederation and #SingleSPA are genius inventions. But step back for a second. What were #WebComponents supposed to give us? Framework-agnostic components. Isolation. Independent shipping. Browser-level boundaries. Now look at what we’re doing in 2025: Managing shared React singletons in webpack configs. Debugging version conflicts at runtime. Shipping duplicate frameworks because “team autonomy.” Rebuilding isolation in JavaScript instead of using the platform. That should feel weird. Web Components didn’t fully take off for large apps. The #ShadowDOM complicated theming. The ecosystem never matched #React. DX friction was real. So instead of fixing that… we moved the complexity into tooling. And here’s the part nobody likes saying out loud: Most Micro Frontend setups eventually drift back to: A #monorepo. Build-time integration. Shared dependencies. Feature flags. Strong #CICD pipelines. In other words: a well-architected #monolith. Boring wins. Ironically, Web Components did succeed in one place: #DesignSystems. Stable UI primitives shared across #Angular, #React, even vanilla apps? That works beautifully. But splitting entire product slices into runtime islands because teams can’t coordinate? That’s usually not a technical scaling problem. That’s a communication problem. Full breakdown in my latest article: 👉 https://lnkd.in/enZSR_Vv If you’re building or considering #MicroFrontends, this one’s worth a read. #WebComponents #ModuleFederation #SingleSPA #React #Angular #JavaScript #WebDevelopment #FrontendArchitecture #SoftwareArchitecture #SystemDesign #Monorepo #Nx #Turborepo #EngineeringCulture #DeveloperExperience #DX #TechLeadership #ScalableArchitecture #BuildInPublic #UnderTheHood

In my latest project, I broke down the two most common approaches to frontend architecture. Here is how they compare in the real world: 🧱 The Monolith Approach In a monolithic setup, everything—Home, Products, Cart, and Profile—is bundled together. The Code: Everything loads at once, which can slow down that critical initial page load. The Catch: Every single state change re-renders the ENTIRE page. Best For: Small to mid-sized teams and early-stage startups that need simplicity and fast initial development. 🧩 The Micro Frontend Approach This approach treats your UI as a collection of independent features owned by separate teams. Lazy Loading: Components like RemoteProducts or RemoteCart load ONLY when the user actually needs them. Memoization: Using React.memo ensures your Profile doesn't waste resources re-rendering when the Cart updates. Error Boundaries: If the Cart fails, it doesn't take down the whole app. The rest stays up while the user sees a helpful fallback. Best For: Large, distributed teams that need to deploy independently without blocking each other. The Bottom Line: Don't move to Micro Frontends just because it's trendy. Move when your team size makes a monolith a bottleneck. Which one are you currently using? Let’s discuss in the comments! 👇 #MicroFrontends #FrontendArchitecture #Monolith #WebDevelopment #SoftwareEngineering #SystemDesign #ReactJS #Angular #VueJS #TechLeadership #ScalableSystems #CodingTips #CleanCode #Javascript

𝗙𝗿𝗼𝗺 𝘀𝗹𝗼𝘄 𝗮𝗻𝗱 𝘀𝘁𝗿𝗲𝘀𝘀𝗳𝘂𝗹 𝘁𝗼 𝗳𝗮𝘀𝘁 𝗮𝗻𝗱 𝘀𝗰𝗮𝗹𝗮𝗯𝗹𝗲 — 𝘁𝗵𝗮𝘁’𝘀 𝘁𝗵𝗲 𝗥𝗲𝗮𝗰𝘁 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝗰𝗲. . . . BEFORE React… Slow-loading pages. Messy, repetitive code. Tiny UI changes were breaking the entire layout. Scaling felt risky. Stressful. Expensive. Every update = more complexity. Every feature = more chaos. Then React happened… Smooth transitions. Instant updates. Clean structure. A frontend that actually works with you — not against you. AFTER React ➡️ Reusable components that save time ➡️ Fast rendering for seamless user experience ➡️ Clean, maintainable architecture ➡️ Scalable structure built for growth No more rebuilding from scratch. No more performance bottlenecks. No more frontend headaches. Just powerful, flexible, future-ready applications designed to scale as your business grows. Because modern brands don’t just need websites — they need dynamic, high-performing digital experiences. “Build once. Scale smoothly. Grow confidently.” Ready to transform your frontend? Upgrade with Devace Technologies and unlock smart, scalable React development that moves as fast as your vision. . . . #ReactJS #FrontendDevelopment #Devace #WebDevelopment #TechInnovation #UIUX #JavaScript #ScalableApps

𝗠𝗼𝘀𝘁 𝗥𝗲𝗮𝗰𝘁 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿𝘀 𝗠𝗶𝘀𝘂𝘀𝗲 𝗜𝗻𝗵𝗲𝗿𝗶𝘁𝗮𝗻𝗰𝗲 And over time, it quietly damages component architecture. The better approach? ✅ 𝗖𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗶𝗼𝗻 Here’s the mental model I follow when building UIs with React 👇 Instead of creating large components and extending them through inheritance… Break your UI into small, reusable building blocks — and compose them together. ❌ 𝗜𝗻𝗵𝗲𝗿𝗶𝘁𝗮𝗻𝗰𝗲 𝗔𝗽𝗽𝗿𝗼𝗮𝗰𝗵 You start with a base Button and extend it: • PrimaryButton • SecondaryButton • LoadingButton Every new variation becomes a new component subtype. Over time, this leads to rigid and hard-to-maintain hierarchies. ✅ 𝗖𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗶𝗼𝗻 𝗔𝗽𝗽𝗿𝗼𝗮𝗰𝗵 Instead, compose behavior: • <Button /> • <LoadingButton /> • <BackButton /> Each component adds behavior without modifying the base component. 𝗪𝗵𝘆 𝗖𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗶𝗼𝗻 𝗪𝗶𝗻𝘀 Inheritance often forces you to create new subclasses for every variation. Composition lets you 𝗺𝗶𝘅 𝗯𝗲𝗵𝗮𝘃𝗶𝗼𝗿𝘀 𝗳𝗿𝗲𝗲𝗹𝘆. That makes components: • Easier to reuse • Easier to extend • Easier to maintain 𝗔𝗻𝗼𝘁𝗵𝗲𝗿 𝗪𝗮𝘆 𝘁𝗼 𝗧𝗵𝗶𝗻𝗸 𝗔𝗯𝗼𝘂𝘁 𝗜𝘁 Composition keeps your base components: Closed for modification, but open for extension. This aligns perfectly with the Open/Closed Principle. 𝗔 𝗦𝗶𝗺𝗽𝗹𝗲 𝗥𝘂𝗹𝗲 𝗜 𝗙𝗼𝗹𝗹𝗼𝘄 When building React UIs: If you feel tempted to extend a component… Pause. Ask yourself: “𝗖𝗮𝗻 𝗜 𝗰𝗼𝗺𝗽𝗼𝘀𝗲 𝘁𝗵𝗶𝘀 𝗶𝗻𝘀𝘁𝗲𝗮𝗱?” Most of the time, the answer is yes. And your codebase will thank you for it. 💾 Save this for future reference ♻ Repost to help other React developers 👥 Share with your frontend team #ReactJS #FrontendEngineering #JavaScript #SoftwareArchitecture #CleanCode #WebDevelopment #Programming #DeveloperExperience #SoftwareEngineering

Frontend Learning: Stop Thinking in Pages. Start Thinking in Systems. When building applications with React, most developers naturally think in terms of pages — Login page, Dashboard page, Profile page. That works in the beginning. But as the application grows, page-based thinking starts creating: Duplicate components Repeated API logic Inconsistent UI patterns Hard-to-maintain state management 🔎 The System-Based Approach Instead of building isolated pages, think in reusable systems: 🔐 Authentication system 📦 Data fetching system 📝 Form handling & validation system 🎨 Design system (buttons, inputs, layout primitives) 🔔 Notification system Now each page becomes a composition of systems — not a standalone structure. 💡 Why This Matters at Scale When you think in systems: ✔ Features become easier to extend ✔ Logic becomes reusable across modules ✔ UI stays consistent ✔ Refactoring becomes less painful ✔ Teams collaborate more efficiently This is how large production apps stay maintainable. 📌 Senior Takeaway: Pages deliver features. Systems deliver scalability. Frontend architecture maturity starts when you move from “building screens” to “building reusable foundations.” Are you still structuring apps page-first, or system-first? #FrontendLearning #ReactJS #FrontendArchitecture #CleanCode #WebDevelopment