Fixing React Parcel Error with Incorrect Main Field

🚨 Storing secret keys in React's .env file? You're exposed. REACT_APP_STRIPE_SECRET_KEY=sk_live_abc123 Looks safe. It's not. React runs in the browser. When you run npm run build, your .env variables get bundled into the JavaScript files. Anyone can hit F12 and read your secret key in plain text. The fix is simple 👇 Never call third-party APIs directly from React. Call your own backend instead — and let the backend handle the secret keys. .env in React is fine for public URLs, feature flags, and app environment. Not for secrets. Simple rule → if you'd be embarrassed for anyone to see it, it doesn't belong in React. Have you ever made this mistake? 👇 #ReactJS #JavaScript #WebDevelopment #Security #Frontend

Behind the Screen – #34 Do you know? The #node_modules folder is often larger than your entire project. Why is it so big? 👉 Your project depends on many #packages   👉 Each package has its own #dependencies   👉 Those dependencies have their own dependencies  This creates a dependency tree. So when you #install one library, you might actually be installing hundreds of smaller packages. Also: 👉 Packages include multiple files (code, configs, docs)   👉 Different versions may coexist   👉 Everything is stored #locally for faster usage  That’s why node_modules grows so quickly. It may look heavy, but it helps your app run without fetching things again and again. 🔥 One install command can bring an entire ecosystem into your project. #javascript #reactjs #webdevelopment #techfacts #developer

Most developers treat React and ASP.NET Core as two separate worlds. Frontend does its thing. Backend does its thing. And somewhere in the middle, things break. Here's what actually makes a React + .NET Core stack solid: → A clean API contract (typed DTOs, no random object returns) → Axios interceptors handling auth tokens globally — not per request → Role-based route guards on both the frontend AND the controller level → Centralized error handling so the UI never shows a raw 500 I've built all of this from scratch in a real production app. The mistakes you make when these two don't talk properly are expensive. Follow if you're building full-stack with React + .NET Core. I share what actually works in production — not textbook theory. #dotnet #aspnetcore #reactjs #fullstackdevelopment #webdevelopment #csharp #softwaredevelopment

Are you a React developer? Still using react-router-dom? Time to upgrade. React Router v7 isn’t just an update, it’s a complete rewrite. What changed: - react-router-dom (legacy) → react-router (unified package) - Built on Remix architecture → faster and more efficient - Improved data loading and prefetching - Stronger TypeScript support - NavLink now has built-in active state handling - One package for web, native, and server - Actively maintained, future-proof If you are starting a new project, go straight to v7. Same API, better foundation, future-ready routing. Check the comment section for link to the documentation #reactjs #frontend #javascript #reactrouter #reactrouterdom

Most React apps have a performance killer hiding in plain sight. It's unnecessary re-renders. Here's how to stop them: 1️⃣ Use React.memo() for pure components   → Skips re-render if props haven't changed 2️⃣ useMemo() for expensive calculations   → Only recalculates when dependencies change 3️⃣ useCallback() for function props   → Prevents child re-renders caused by new function references 4️⃣ Lift state only where needed   → Don't store everything in a top-level component 5️⃣ Use React DevTools Profiler   → Visualize exactly what's re-rendering and why Bonus: The React Compiler (coming to React 19) will handle much of this automatically. But understanding the problem still makes you a better engineer. Save this for your next performance audit. 🔖 #React #ReactJS #JavaScript #WebPerformance #Frontend

🚀 I recently completed the Next.js section from Jonas Schmedtmann’s Ultimate React Course 2025 and built this project while following along. As part of that, I developed “The Wild Oasis” — a production-style application focused on real-world architecture and authentication. 🔗 Live Demo: https://lnkd.in/dsX6jwGg 💡 What I implemented: • Full authentication system using Auth.js with Google OAuth • Protected routes, session management, and user dashboards • Next.js App Router with nested layouts and dynamic routing • Server Components & Server Actions for better performance • Error handling and loading states using Suspense ⚙️ Tech Stack: Next.js 16, Auth.js, Supabase, React 18 This part of the course really helped me understand how to build secure, scalable, production-ready applications with Next.js. #NextJS #React #WebDevelopment #Frontend #FullStack #JavaScript #AuthJS

You don't need as much React state as you think. Most developers reach for `useState` by default. But a lot of "state" is already living somewhere else — in the URL, in server responses, in the route itself. Deriving UI from those sources keeps your app simpler, more shareable, and easier to debug. Instead of this: const [tab, setTab] = useState('overview'); Try this: const tab = new URLSearchParams(location.search).get('tab') ?? 'overview'; Now the active tab survives a refresh, works with the back button, and can be shared via link — all for free. The same principle applies on the server side. Whether you're working with Node.js, a .NET API, or a C# backend, let the server be the source of truth. Fetch it, derive from it, don't duplicate it. Less state means fewer bugs, fewer re-renders, and less mental overhead. Where are you still using local state that could live in the URL or server data instead? #React #JavaScript #WebDevelopment #Frontend #DotNet #NodeJS

⚛️ React.js Performance Optimization Cheat Sheet In this guide, we'll go over some techniques you can use to improve the performance of your React apps. ✅ React.memo ✅ useMemo/useCallback ✅ Code splitting ✅ Virtualization ✅ Handler/object allocation ✅ Keys for lists ✅ Minimal state ✅ Profiling & monitoring Save & share with your team! Download Our Free Full-Stack Developer Starter Kit ➡️ https://lnkd.in/gvzdeSJn --- If you found this guide helpful, follow TheDevSpace | Dev Roadmap, w3schools.com, and JavaScript Mastery for more tips, tutorials, and cheat sheets on web development. Let's stay connected! 🚀 #React #Performance #JavaScript #WebDevelopment #CheatSheet #Frontend #Coding

Here's how I would approach performance debugging in React. When something feels slow, the first thing I would open is the network tab. Because before forming any opinion, I want to see what’s actually being sent to the browser. - How much is loading. - What’s blocking the page. - What’s there that probably shouldn’t be. That’s usually where the obvious stuff shows up. For example, locale files for regions nobody uses. Modules loading upfront for routes the user hasn’t even visited yet etc. Once I have a rough picture, I would run Lighthouse. Not for the score, but to have a baseline I can track. Then comes the bundle analyser. It tells me which packages are heavy. Are there any duplicate packages I can get rid of? What could be lazy loaded but isn’t? If the load looks fine but the app still feels slow, I would open React DevTools Profiler. It can help with checking if any components are re-rendering when it shouldn’t. The order matters more than the tools. Most performance problems I’ve seen aren’t complicated. They’re just unmeasured. #React #Frontend #WebPerformance #JavaScript #TypeScript

A slow page isn’t always a slow server. Sometimes it’s just your app downloading a lot of code the user will never actually use. We ran into this while migrating a large legacy frontend to React. The initial load was pulling in routes the user hadn’t visited and features behind flags most people would never trigger. All of it bundled together and shipped on every page load. The fix was surprisingly simple. Stop sending code the user doesn’t need yet. We split bundles by route so each page loads its own code only when the user navigates there. Heavy components were further down the page load on demand instead of during startup. The main bundle dropped by about 30 percent and the initial load got noticeably faster by just being a bit more intentional about what goes to the browser. A lot of performance problems aren’t complicated. They happen because nobody stopped to ask one simple question. Does the user actually need this right now? #Frontend #React #WebPerformance #JavaScript