Giorgio Cangemi’s Post

🚨 The “Invisible” Update: Why Your React UI Might Be Stuck Ever faced a bug where you know the data is there… but your UI just refuses to show it? I recently ran into this while working on a table: Data was fetched successfully ✅ Most columns rendered fine ✅ But one column kept showing empty/null ❌ 🕵️♂️ The Culprit: useRef We were storing incoming async data in useRef. At first glance, everything looked correct: Data was arriving ✔ Ref was updating ✔ But here’s the catch 👇 👉 The column that depended on slightly delayed data never re-rendered 👉 So the UI stayed stuck in its initial empty state ⚠️ Why This Happens useRef: Persists values across renders ✅ Does NOT trigger re-render on update ❌ So even when the data eventually arrived, React had no reason to update the UI. ✅ The Fix: Use useState Switched from useRef → useState const [data, setData] = useState(null); Now: As soon as data updates → component re-renders 🔁 Table updates automatically → no more empty column 🎯 #React #FrontendDevelopment #JavaScript #WebDev #SoftwareEngineering

The "Ghost in the API": How I fixed a major rendering lag 👻 While working on a complex user dashboard at Codes Thinker, I encountered a frustrating performance bottleneck. Every time a user triggered a data fetch, the entire UI would "freeze" for a split second before updating. Even with a fast backend API, the user experience felt "heavy" and unprofessional. The Challenge: We were fetching large, nested JSON objects directly inside a parent component. Every time the API responded, the entire component tree re-rendered, causing a visible performance lag during data transformation. The Solution: React Query: I implemented React Query to handle caching. This ensured that if a user requested the same data twice, the result was instant. Data Transformation: Instead of passing the raw "heavy" object to components, I mapped the data into a lighter format immediately after fetching. Optimistic UI: I used Tailwind CSS to create smooth skeleton loaders, making the app feel faster while the data was still loading. The Result: The rendering lag disappeared, and the user experience became fluid. Sometimes, being a Senior Frontend Developer is about knowing when not to fetch data as much as how to fetch it. Have you ever faced a stubborn API lag? How did you tackle it? Let’s share some dev stories! 👇 #RESTAPI #NextJS #PerformanceOptimization #MERNStack #WebDevelopment #CleanCode #ReactJS #TailwindCSS

"WebAssembly for compute-heavy web apps might be the most transformative advancement in web development that nobody is talking about enough. Isn't it surprising how often we settle for slow JavaScript routines when WebAssembly can offer near-native performance right in the browser? As developers, we constantly chase that sweet spot of performance and accessibility, but we mostly rely on tricks and optimizations that only take us so far. When I first integrated WebAssembly into a predictive analytics tool, the speed gains were immediately noticeable. Tasks that previously took seconds were completed in milliseconds—transforming the user experience. In one project, I was using a simulation model that required intense calculations. JavaScript was simply not up to the task. WebAssembly, however, handled the computational load effortlessly. This wasn't just about improving existing workflows; it opened doors to use cases I hadn't even considered before, like real-time data visualization and complex physics calculations directly in the browser. Here's a quick TypeScript example of how easy it is to call WebAssembly functions from JavaScript: ```typescript const importObject = { env: { memory: new WebAssembly.Memory({ initial: 256 }), table: new WebAssembly.Table({ initial: 0, element: 'anyfunc' }) } }; WebAssembly.instantiateStreaming(fetch('myModule.wasm'), importObject) .then(result => { const { myFunction } = result.instance.exports; console.log(myFunction(42)); // Use the exported function }); ``` Have you tried WebAssembly in your projects? What are the compute-heavy tasks that you think could benefit most from this technology? Let's discuss how we can leverage it to push the boundaries of web performance and user experience." #WebDevelopment #TypeScript #Frontend #JavaScript

🚀 Stop treating Server State like UI State. As React developers, we’ve all been there: building "custom" fetching logic with useEffect and useState. It starts with one loading spinner and ends with a nightmare of manual cache-busting and race conditions. When I started migrating my data-fetching to TanStack Query, it wasn't just about "fewer lines of code"—it was about a shift in mindset. The Real Game Changers: Declarative vs. Imperative: Instead of telling React how to fetch (and handle errors/loading), you describe what the data is and when it should be considered stale. Focus Refetching: This is a huge UX win. Seeing data update automatically when a user switches back to the tab feels like magic to them, but it’s just one config line for us. Standardized Patterns: It forces the whole team to handle errors and loading states the same way, which makes code reviews much faster. The Win: In a recent refactor, I replaced a tangled mess of global state syncs and manual useEffect triggers with a few useQuery hooks. I was able to delete a significant chunk of boilerplate while fixing those "stale data" bugs that always seem to haunt client-side apps. The takeaway: Don't reinvent the cache. Use tools that let you focus on the product, not the plumbing. 👇 Question for the devs: Are you using TanStack Query for everything, or are you finding that Next.js Server Actions and the native fetch cache are enough for your use cases now? #reactjs #nextjs #frontend #webdev #tanstackquery #javascript

Your React Native screen is not “messy” It’s lying to you. It looks fine. It works. It even gets shipped to production. But the moment you try to change something small, everything starts behaving unpredictably. Why? Because the problem was never visible. I faced this exact situation recently. One screen. Everything inside it. API calls State logic Data transformation UI rendering At first, it felt efficient. One place. Easy to manage. In reality, it was a trap. Every change had side effects. Every bug took longer to trace. Every new feature felt heavier than the last one. That’s when I made a shift most developers avoid. I stopped thinking in screens. I started thinking in layers. I pulled API logic out into a separate layer. Suddenly, external dependencies stopped leaking everywhere. I moved business logic into custom hooks. Now decisions lived in one place instead of being scattered. I stripped the screen down to just UI. No logic. No side effects. Just rendering. And something interesting happened. The same feature that once felt complex became predictable. Not easier. Predictable. That’s the difference between mid-level and senior thinking. You don’t reduce complexity. You control where it lives. If your screen is doing everything, you don’t have a screen. You have a system pretending to be simple. Fix the structure, and everything else starts fixing itself. - UI should only render - Hooks should control logic - Services should handle data This is where real engineering starts.

🚀 Excited to share: react-pivot-pro is now live on npm! After a lot of iteration, debugging, and refining real-world use cases, I’ve finally published a powerful pivot table solution built to make complex data interactions simple, flexible, and production-ready. 🔗 https://lnkd.in/gfNR-DT2 💡 Why I built this Working with large datasets in frontend apps often means dealing with: • Aggregations • Dynamic grouping • Performance bottlenecks • Poor developer experience Most existing solutions are either too rigid or not extensible enough. react-pivot-pro is designed to solve that — with a focus on flexibility and real-world usability. ⚙️ What it offers • Dynamic pivoting (rows, columns, values) • High-performance data processing • Plugin-based architecture • Type-safe APIs • Developer-first design • Easy dashboard integration 🧪 Built with real problems in mind This isn’t a demo-first library — it’s shaped by: • Fixing broken implementations • Handling real edge cases • Ensuring examples actually work (no assumptions) 📘 What’s next • 100% example coverage • Deep documentation with real-world scenarios • Advanced dashboard integrations • More customization capabilities 🙌 Looking for feedback If you're building: • Data-heavy apps • Internal dashboards • Analytics platforms I’d love your feedback and use cases. 📦 Try it out npm install react-pivot-pro Aiming to make pivot tables actually developer-friendly. #React #OpenSource #JavaScript #Frontend #DataVisualization #TypeScript #WebDevelopment #npm

Most React developers start API calls with useEffect(). It works. Until the project gets bigger. Then suddenly: ❌ Manual loading state ❌ Manual error handling ❌ Duplicate API calls ❌ No caching ❌ Refetch logic becomes messy ❌ Background sync becomes difficult ❌ Race conditions become common And your component starts doing too much. That’s when you realize: useEffect is not a data-fetching solution. It is a side-effect hook. That’s where React Query changes everything. useEffect helps you run effects. React Query helps you manage server state. That difference is huge. Use useEffect() for: ✔ Timers ✔ Event listeners ✔ Subscriptions ✔ External system sync ✔ Simple one-time logic Use React Query for: ✔ API fetching ✔ Response caching ✔ Auto refetching ✔ Pagination ✔ Infinite scroll ✔ Mutations ✔ Background updates ✔ Optimistic UI The biggest mistake is using useEffect like a mini backend framework. It was never designed for that. Better architecture: Client state → useState() / useReducer() Server state → React Query That separation creates: ✔ Cleaner code ✔ Better UX ✔ Faster applications ✔ Less debugging ✔ Predictable state management Good React code is not about using fewer libraries. It is about using the right tool for the right problem. Sometimes the best optimization is removing unnecessary code—not adding more. What do you prefer for API calls in production apps: useEffect() or React Query? 👇 #ReactJS #ReactQuery #useEffect #FrontendDevelopment #JavaScript #StateManagement #WebDevelopment #SoftwareEngineering

In this post, I focused on visualizing how data moves within a React application using a Data Flow Diagram (DFD). Understanding data flow allows developers to: • Build more organized and scalable applications • Avoid unnecessary complexity and bugs • Clearly separate logic from UI • Improve maintainability and readability This approach helped me move beyond writing components to truly understanding how data drives the entire application. #React #Frontend #WebDevelopment #JavaScript #SoftwareArchitecture #CleanCode

Who really owns your form data? In a standard HTML input, the DOM is the boss. It holds the value in its own internal memory, and you only "ask" for it when the user hits submit. But in React, we don't like hidden state. We want every piece of data to be explicit and predictable. This is where Controlled Components come in. In this pattern, the React state is the single source of truth. The input doesn't maintain its own value. Instead, you tell the input exactly what to display using the 'value' prop, and you update that value through an 'onChange' handler that modifies the state. The input is "controlled" because its behavior is entirely driven by the React component. Why go through this extra boilerplate? It gives you total coordination over the UI. Since the data lives in your state, you can perform instant field validation, disable the submit button based on specific criteria, or even format the user's input in real-time. There is no "syncing" issue between the DOM and your logic because they are never out of alignment. Of course, controlling every single character stroke in a massive form can feel like overkill. For simple, high-performance scenarios where you just need the data at the end, Uncontrolled Components using 'refs' might be faster. But for most applications, the predictability of a controlled flow far outweighs the cost of a few extra lines of code. It ensures that what the user sees is exactly what your application "knows". #ReactJS #SoftwareEngineering #WebDevelopment #FrontendArchitecture #CodingTips #Javascript

𝐌𝐚𝐬𝐭𝐞𝐫𝐢𝐧𝐠 𝐒𝐭𝐚𝐭𝐞 𝐋𝐨𝐠𝐢𝐜 & 𝐂𝐑𝐔𝐃 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐨𝐧𝐬 ⚛️ Yesterday was about the "comeback," but today is about the "consistency." I spent my session diving into dynamic data management—building a Name Manager that handles full CRUD (Create, Read, Update, Delete) logic. To move from static pages to interactive apps, I focused on these three technical pillars: 🔹 𝐮𝐬𝐞𝐒𝐭𝐚𝐭𝐞 (𝐓𝐡𝐞 𝐌𝐞𝐦𝐨𝐫𝐲): In React, components reset on every render. useState acts as the persistent "brain," allowing the app to remember data even when the UI updates. I practiced using setter functions to trigger re-renders safely. 🔹 .𝐦𝐚𝐩() (𝐓𝐡𝐞 𝐔𝐈 𝐅𝐚𝐜𝐭𝐨𝐫𝐲): This is how we turn raw data into an interface. It loops through an array and transforms strings into interactive components. It’s the engine behind every dynamic list you see online. 🔹 .𝐟𝐢𝐥𝐭𝐞𝐫() (𝐓𝐡𝐞 𝐈𝐦𝐦𝐮𝐭𝐚𝐛𝐥𝐞 𝐃𝐞𝐥𝐞𝐭𝐞): React rule #1: Don't mutate state. Instead of "erasing" data from the original array, I used .filter() to create a brand-new copy. This is the secret to building predictable, bug-free applications. 𝐖𝐡𝐚𝐭 𝐈 𝐢𝐦𝐩𝐥𝐞𝐦𝐞𝐧𝐭𝐞𝐝 𝐭𝐨𝐝𝐚𝐲: ✅ Create: Added new entries using the Spread Operator [...]. ✅ Read: Rendered a dynamic, real-time list with .map(). ✅ Update/Delete: Built the logic to modify and remove specific items without breaking the state. 𝐓𝐡𝐞 𝐁𝐢𝐠 𝐓𝐚𝐤𝐞𝐚𝐰𝐚𝐲: In React, we don't modify the past; we create a fresh copy of the future! 🚀 #ReactJS #WebDevelopment #JavaScript #FrontendDeveloper #LearningInPublic