React 19.2.0: New Features and Improvements

Day 2 of 11:11 Series React 19.2: Effect vs. Effect Event (API Edition) Yesterday, I explored the fresh activity-based updates React 19.2 brings to our dev toolkit. But today, I want to share something that solves a REAL pain point in our codebases—the subtle but super important distinction between side effects and event handlers in React. What’s the Issue? 🤔 Ever faced this situation: You’re fetching data from multiple APIs in a single useEffect, You display a toast, log a notification, or update the UI with a value (like a theme or message) every time data arrives. But then, when any prop changes (like the theme), the whole effect re-runs and APIs refetch. Not ideal right 🤔 ! Problem: When you want only the notification style (theme) to update, but NOT refetch APIs—this dependency forces all effects to re-run. The Solution: useEffectEvent! React 19.2 introduces useEffectEvent to separate side effect subscriptions from handlers responding to those effects. You fetch APIs only when you want, and notify with the latest theme without refetching! No unnecessary API calls! useEffectEvent decouples side API calls from cosmetic/UI logic, keeping your API fetches efficient while your handlers always use up-to-date props/state. Drop your thoughts below—how else would you use this pattern? #React19 #Hooks #APIIntegration #FrontendTips #DeveloperSeries Read More: [https://lnkd.in/gNSpWx-D]

Control is the name of the game in Next.js 16. This release gives developers explicit control over the core of their application, making maintenance and performance optimization much simpler: * Cache Components & use cache: No more implicit caching! Gain granular control over what gets cached, making complex parts of your app predictable and easier to debug. * Turbopack is the Default: The lightning-fast build system is now stable and the default, bringing huge performance and stability gains to your entire development and production workflow. * Refined Caching APIs: New functions like updateTag() and a more powerful revalidateTag() offer precise, granular control over data invalidation, giving you "read-your-writes" consistency. If you're building large, data-intensive applications, these features will be game-changers for your architecture. #NextJS16 #DeveloperExperience #Caching #Turbopack #React

Running LangChain ReactAgent in browser LangChain is the easiest way to start building agents and applications powered by LLMs. It provides a pre-built agent architecture and model integrations to help you get started quickly and seamlessly incorporate LLMs into your agents and applications. ———— LangChain v1.0 is now available! The createAgent() function provides a production-ready agent implementation that’s remarkably simple to use: import { createAgent } from "langchain"; const agent = createAgent({ model: "gpt-5", tools: [] }); However, when attempting to use this function within a useEffect() hook in a Next.js project, I encounter a frustrating error: Upon investigation, the root cause becomes clear. The context.js file contains the line: import { AsyncLocalStorage } from "node:async_hooks"; Unfortunately, node:async_hooks is not supported in browser environments. Import traces: Client Component Browser: ./node_modules/@langchain/core/dist/context.js [Client Component Browser] ./node_modules/langchain https://lnkd.in/gpW-Tw_E

🎯 Next.js 16 Has Arrived: A Comprehensive Technical Deep-Dive I'm excited to share my latest technical article covering the groundbreaking Next.js 16 release—arguably the most significant update in the framework's history. Key Highlights from My Analysis: 📊 Performance Metrics: • 2-5× faster production builds with Turbopack (now stable and default) • 10× improvement in Fast Refresh during development • 98% reduction in network transfer for shared layouts 🏗️ Architecture Evolution: • Cache Components with explicit "use cache" directive • Granular control over static/dynamic content via PPR • New proxy.ts replacing middleware for clearer boundaries 💡 Developer Experience: • AI-assisted debugging through MCP integration • Enhanced logging with detailed timing breakdowns • Simplified create-next-app with modern defaults 🔧 Enterprise Impact: • Reduced build times saving thousands of developer hours • Lower infrastructure costs through optimized caching • Improved Core Web Vitals out of the box In my comprehensive guide, I break down each feature with practical examples, migration strategies, and real-world use cases from e-commerce to SaaS applications. The shift from implicit to explicit caching alone will revolutionize how we approach web application architecture. Combined with Turbopack's performance gains, teams can now iterate faster while maintaining production stability. 📖 Full Technical Analysis: https://lnkd.in/gbydZ_vf I'd love to hear your thoughts on how these changes might impact your current projects. What challenges do you think this release solves for your team? #NextJS #WebArchitecture #SoftwareEngineering #TechnicalLeadership #ReactJS #FullStackDevelopment #PerformanceOptimization #DeveloperProductivity #TechInnovation #WebDevelopment

𝐍𝐞𝐱𝐭.𝐣𝐬 16 𝐑𝐞𝐥𝐞𝐚𝐬𝐞𝐝: 𝐅𝐨𝐜𝐮𝐬𝐞𝐝 𝐨𝐧 𝐒𝐩𝐞𝐞𝐝, 𝐂𝐨𝐧𝐭𝐫𝐨𝐥, 𝐚𝐧𝐝 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 𝐄𝐟𝐟𝐢𝐜𝐢𝐞𝐧𝐜𝐲 After diving into Next.js 16, it’s clear this release focuses on giving developers deeper control over performance and smarter tooling for modern web apps. Here’s what stands out in this release: 1. Cache Components The new "use cache" directive gives developers control over what to cache — improving load times reducing server strain. 2. Turbopack (Stable) Now the default bundler, Turbopack delivers much faster builds and refresh times for new apps. 3. React Compiler Support With automatic memoization built-in, React now skips unnecessary re-renders. 4. Smarter Routing & Prefetching Page transitions feel smoother, and the logs now provide much clearer visibility. 5. AI-Assisted DevTools (MCP Integration) MCP brings AI-powered insights into DevTools, helping developers identify performance and caching issues in real time. In short, Next.js 16 sets a new benchmark for building high-performance, intelligent web applications.

New react feature <Activity /> Usage: - Hide part of your application - Restore the state of hidden components Why use it not old ? <Activity> gives you more control over hidden content. It stays hidden but keeps its state connected, preventing unwanted side effects. This makes it more efficient and smoother to use It’s an alternative to repeatedly unmounting and mounting UI sections when toggling their visibility باختصار : mount / unmount بتمنع المشاكل اللي بتحصل لما تعمل يعني بتخلي الأداء أسرع والتحكم أسهل في المحتوى المخفي docs : https://lnkd.in/d3A_vy9b

📣 New blog post is live! “API’s Explained | HTTP vs RPC” by Mikhail Karan In this piece: ✅ What distinguishes HTTP-style APIs (REST/GraphQL) from RPC-style APIs (function/method calls) htmlallthethings.com ✅ Code examples showing both approaches ✅ A comparison of developer experience, type safety, standardization and when to choose each ✅ Real-world recommendations: internal apps vs public APIs Whether you’re building a new service or rethinking an existing architecture - this blog post gives concrete guidance to help you make the right call. 👉 Dive in and let us know which side you’re on — HTTP or RPC? 🗞️ https://lnkd.in/gd_85yRD #DeveloperBlog #APIArchitecture #WebDev #BackendEngineering #TypeScript #HTMLAllTheThings #TechInsights

Let's talk about the common Mistakes that we often do while using the useState hook 1️⃣ Expecting state to update instantly setCount(5); console.log(count); // still old value React batches updates and re-renders later so you won’t see the new value immediately. 2️⃣ Updating state directly count = 10; ❌ // This won’t work Always use the updater function. React needs it to trigger a re-render. 3️⃣ Depending on stale values If you’re updating based on the previous state, always use the functional updater form. 🔴Multiple States in One Component You can call useState multiple times to manage different pieces of state: const [name, setName] = useState(''); const [age, setAge] = useState(0); const [isActive, setIsActive] = useState(true); Or, you can use a single state object but remember, updating it doesn’t merge automatically like class components did: const [user, setUser] = useState({ name: "'', age: 0 }); setUser({ ...user, name: '"Alice"}); // must spread previous state ⚙️ React 18 and State Updates With React 18’s automatic batching, multiple state updates in the same tick get batched together: setCount(c => c + 1); setName("John"); Only one re-render, not two. That’s React taking care of the performance behind the scenes. :) #React #useState #Frontend

Yay! #NextJs #16 was released today! TL:DR; Briefly, we have: • Cache Components • Turbopack is enabled by default • Turbopack file system caching (beta) • Optimized navigation and prefetching • Improved caching APIs • Build Adapters API (alpha) • React 19.2 Key features include #Turbopack becoming the default and stable bundler with up to 10x faster Fast Refresh and 2-5x faster builds, enhanced routing with layout deduplication and incremental prefetching, and a new caching model using #Cache #Components for instant navigation through Partial Pre-Rendering. Why that matters: explicit caching, faster iterations, and clearer network boundaries reduce the biggest sources of Next.js complexity in real teams. If you bounced off earlier, implicit caching or middleware surprises, 16 is worth a serious look. Additionally, React 19.2 includes new hooks and features, as well as improved debugging tools with Model Context Protocol (#MCP) integration. The #middleware system has been renamed to proxy.ts for clearer network boundaries. #Logging improvements provide detailed timing for build and render steps. Breaking changes involve async params and next/image defaults. The release aims to make page transitions leaner, faster, and reduce network transfer sizes with no required code changes. Overall, #NextJs #16 focuses on speeding development, optimizing navigation, and refining caching for modern web apps, but some advanced features remain in beta or alpha stages for future maturation. I am testing 16 against production-scale repos this week. Reply with the metrics you want to see: build times, navigation timing, cache hit rates, or your package compatibility list.

React Old vs New: Handling Loading States the Smarter Way Comparison between traditional manual loading state handling and the new automatic approach in React 19. Before React 19 Developers had to manually manage isLoading flags, conditional renders, and spinners — leading to repetitive boilerplate code. Now (React 19 <Loading /> Component) The new <Loading /> component integrates with Suspense to automatically handle loading states during async data fetching. Key Features Highlights of the new loading system in React 19: Automatic Loading State Handling — No need for manual flags. Built-in with Suspense — Works seamlessly with async components. Customizable UI — Replace <Loading /> with your own spinner or skeleton. Cleaner Code, Less Re-renders — Declarative and efficient.