From JavaScript to Rust or Go: Choosing the Right Tool

🚨 The #1 JavaScript mistake that's secretly slowing you down! 💡 I used to chain `.map().filter().map()` everywhere thinking I was writing "clean code." Then one day, my colleague showed me the performance monitor on a large dataset. 47ms vs 8ms. I was mortified. Here's the fix that changed everything: // ❌ Before: Multiple iterations const result = users  .map(u => u.age)  .filter(age => age >= 18)  .map(age => age * 2); // ✅ After: Single iteration const result = users.reduce((acc, u) => {  if (u.age >= 18) acc.push(u.age * 2);  return acc; }, []); 🎯 One pass. Same result. 5x faster on large arrays. The lesson? Elegant ≠ Efficient. Always profile your code with real data before optimizing for "readability." 🔥 Which coding myth would you like busted next? Follow for more bite-sized tech wisdom that actually moves the needle. #JavaScript #WebDev #Coding #TechTips #FrontEndDev #PerformanceOptimization #CleanCode

👋 Bye bye useMemo and usecallback For years, we've manually wrapped functions and values in these hooks to prevent unnecessary re-renders. While powerful, they add boilerplate and are often missed or incorrectly applied. 🚀 **The Big Update:** The **React Compiler** (originally called React Forget) is designed to automatically identify stable values and dependencies, and then *automatically* memoize your components, hooks, and variables. **What This Means For You:** 1. **Cleaner Code:** Significantly reduced need for manual `useMemo`, `useCallback`, and `React.memo()`. Less boilerplate means easier-to-read, maintainable code. 2. **Faster Performance:** Consistent, automatic memoization ensures *only* necessary components re-render, optimizing performance right out of the box, even for developers new to React. 3. **Simpler Mental Model:** You can go back to writing clean, idiomatic JavaScript without constantly worrying about the memoization dance! This is a massive step towards making React's performance model simpler and more accessible. What are your thoughts on this major update? Are you ready to delete hundreds of lines of memoization code? 👇 #React #React19 #WebDevelopment #Frontend #JavaScript #ReactCompiler #Performance

𝟵𝟬% 𝗼𝗳 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿𝘀 𝗱𝗼𝗻’𝘁 𝗸𝗻𝗼𝘄 𝗵𝗼𝘄 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗿𝘂𝗻𝘀 𝘂𝗻𝗱𝗲𝗿 𝘁𝗵𝗲 𝗵𝗼𝗼𝗱. 𝗬𝗼𝘂𝗿 𝗯𝗿𝗼𝘄𝘀𝗲𝗿 𝗿𝗲𝗮𝗱𝘀, 𝗰𝗼𝗺𝗽𝗶𝗹𝗲𝘀, 𝗮𝗻𝗱 𝗰𝗹𝗲𝗮𝗻𝘀 𝗶𝘁 - 𝗶𝗻 𝗿𝗲𝗮𝗹 𝘁𝗶𝗺𝗲. 👇 🔹 𝗦𝘁𝗲𝗽 𝟭: 𝗣𝗮𝗿𝘀𝗶𝗻𝗴 (𝗨𝗻𝗱𝗲𝗿𝘀𝘁𝗮𝗻𝗱𝗶𝗻𝗴 𝘁𝗵𝗲 𝗖𝗼𝗱𝗲) • You write JavaScript code. • Your browser has a JavaScript engine - the program that runs your code. • The Parser reads it and breaks it into tokens (small code pieces). • These tokens form an AST (Abstract Syntax Tree) -  a diagram that shows how your code is arranged • If something’s wrong, the parser stops and shows a syntax error. 🔹 𝗦𝘁𝗲𝗽 𝟮: 𝗜𝗻𝘁𝗲𝗿𝗽𝗿𝗲𝘁𝗮𝘁𝗶𝗼𝗻 (𝗘𝘅𝗲𝗰𝘂𝘁𝗶𝗼𝗻 𝗕𝗲𝗴𝗶𝗻𝘀) • The Interpreter turns the AST into Bytecode (instructions the engine can run). • The Bytecode runs inside the engine, not directly on the CPU. • The program starts running after this step. • The engine tracks which parts run often and what data types are used. 🔹 𝗦𝘁𝗲𝗽 𝟯: 𝗝𝗜𝗧 𝗖𝗼𝗺𝗽𝗶𝗹𝗮𝘁𝗶𝗼𝗻 (𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗮𝘁𝗶𝗼𝗻) • The engine finds hot code (functions or loops that run many times). • It sends them to the JIT (Just-In-Time) Compiler, which turns hot code into faster Machine Code during execution. • This Machine Code runs directly on the CPU. • The result - same code, now runs much faster. 🔹 𝗦𝘁𝗲𝗽 𝟰: 𝗔𝗱𝗮𝗽𝘁𝗶𝘃𝗲 𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗮𝘁𝗶𝗼𝗻 (𝗦𝘁𝗮𝘆 𝗙𝗹𝗲𝘅𝗶𝗯𝗹𝗲) • The engine constantly checks how code behaves. • If types or logic change, it re-optimizes the code for the new pattern. • This adaptive process keeps JavaScript dynamic and efficient. 🔹 𝗦𝘁𝗲𝗽 𝟱: 𝗚𝗮𝗿𝗯𝗮𝗴𝗲 𝗖𝗼𝗹𝗹𝗲𝗰𝘁𝗶𝗼𝗻 (𝗖𝗹𝗲𝗮𝗻 𝘁𝗵𝗲 𝗠𝗲𝗺𝗼𝗿𝘆) • When code or data is no longer needed, it’s removed automatically. • The Garbage Collector (GC) finds and clears unused memory. • This keeps memory light and your app smooth. 🔄 𝗙𝘂𝗹𝗹 𝗙𝗹𝗼𝘄: Parsing → Interpretation → JIT Compilation → Adaptive Optimization → Garbage Collection Follow Saurav Kumar for more easy-to-understand Frontend insight. ✨ Would love to know your thoughts 👇 #JavaScript #FrontendDevelopment #WebDevelopment   #JSEngine #ReactJS #Coding #Programming

I had an argument today on a topic which can be skipped very easily (You don't want to miss reading it) The issue was with understanding the following: ↳ setState() ↳ Mutable & Immutable ↳ Deep and Shallow Copy This looks like an easy concept, but if missed, you will keep scratching your head, or just do vibe coding (which is not recommended) const myInitialState = [ { name: 'name', age: 10 }, { name: 'name1', age: 20 }]; ❌ setState(prevState => prevState.sort((a, b) => a.age - b.age)); ✅ setStatet(prevState => { const sorted = [...prevState]; sorted.sort((a, b) => a.age - b.age)); return sorted; }); Q1. Why does updating the older value doesn't work, and the later works? Q2. Creating a copy via [...prevState] is still a shallow copy, then how does React knows something has changed? Answer 1. The reference matters here. When you change something to the older value, the reference doesn't change, and React thinks, it is still unchanged, hence, no re-render trigger, and no UI updates. Answer 2. Even when you create shallow copy, you are creating a new reference. Creating a new array via "[ ]" → Then shallow copy the items using Spread operator. So the reference of sorted and prevState changes. As soon as React sees that in the return, it triggers re-render, as per "Diffing Algorithm". If you have learnt something new, let your friend learn it too via Repost ♻️ P.S. I have bonus questions in the comment section. Let's check how good do you know React #reactjs #react #javascript #coding #programming #softwareengineering #frontend

Interesting discussion of directives in #JavaScript and the #React ecosystem needing the same mental model building in education that developed for C/C++ pragmas. Viktor Lázár drives home that sending people off to use directives without a nuanced understanding of the layered development stack (including syntax, loaders, build tools, and runtime) results in a collapse in their ability to debug. He built a #TypeScript plugin to make directives a little more legible, which looks interesting. What is a good way to encourage stronger mental models around directives? #Frontend #WebDev #ContinuousLearning https://lnkd.in/g-VJSPZq

🚀 I used to think JavaScript was just “interpreted”… Until I discovered how much magic happens before a single line runs. When you write something simple like let sum = 10 + 5, the JS engine doesn’t just read it; it compiles it. Yes, JavaScript is compiled before execution (just-in-time). ⚙️ Here’s what actually happens behind the scenes: 1️⃣ Tokenization – your code is broken into keywords, operators, and identifiers. 2️⃣ Parsing – those tokens form an Abstract Syntax Tree (AST) that maps out the structure of your program. 3️⃣ Interpretation – the AST is turned into bytecode. 4️⃣ JIT Compilation – engines like V8’s TurboFan optimize bytecode into fast machine code. 5️⃣ Garbage Collection – memory is automatically cleaned up when no longer needed. All of this happens in milliseconds ⚡ Every single time your JS runs. I broke down each step in detail in my new Medium article 👇 👉 https://lnkd.in/dM7yNH6f #JavaScript #WebDevelopment #Programming #NodeJS #Frontend #V8 #SoftwareEngineering

🚀Today I learned: How JavaScript executes inside the browser! We all write JavaScript every day — but have you ever wondered what actually happens behind the scenes when we run our code? Here’s what I learned👇 🔹Step-by-step explanation: 1️⃣Source Code → We write JavaScript in a .js file — just plain text that browsers can’t execute directly. 2️⃣Parsing → The JavaScript engine reads the code, checks for syntax errors, and prepares it for further processing. 3️⃣AST (Abstract Syntax Tree) → The code is converted into an AST, a structured tree that represents the program logic in a machine-understandable format.🌳 4️⃣Interpreter → The AST is passed to the interpreter, which converts it into bytecode for quick startup and execution. 5️⃣Execution & Profiling → While executing bytecode, the engine tracks which parts of the code run most frequently — known as “hot” code. 6️⃣Optimizing Compiler (JIT) → The JIT (Just-In-Time) compiler takes that hot code and compiles it into machine code, making it much faster.⚡ 7️⃣Machine Code Execution → Finally, this optimized machine code runs directly on the CPU, giving JavaScript near-native speed and efficiency. 🧠In simple words: JavaScript uses both an Interpreter (for quick startup) and a JIT Compiler (for optimized performance). Really fascinating to see how much happens behind the scenes every time we run a simple JS file!✨ #TodayILearned #JavaScript #WebDevelopment #Frontend #Programming #V8Engine #LearningEveryday #10000coders #SudheerVelpula Special thanks to Sudheer Velpula Sir and @10000 Coders for the amazing learning journey and constant guidance🙌

I spent three hours debugging a production bug yesterday. The fix? A single typo in a property name. JavaScript didn't care. It just returned undefined and kept running. TypeScript would've caught it before I hit commit. That's the whole story, really. JavaScript lets you move fast. Write whatever, run it, see what happens. Perfect for prototypes, small projects, getting ideas out of your head. TypeScript makes you slow down. Define your types. Tell the compiler what you're doing. It argues with you before your code ever runs. Sounds annoying until you're managing a 50,000 line codebase with five developers. Then that compiler arguing with you becomes your best friend. The catch: TypeScript has a learning curve. You'll spend time fighting with type definitions when you just want to ship. For a weekend project, that's overkill. But if you're building something meant to last, something other people will touch, something that needs to scale... TypeScript pays for itself in the bugs you never write. Not a religious debate. Just different tools for different jobs. The question isn't which one is better. It's which one fits what you're building right now.

What is a DIRECTIVE in .js An awesome colleague I used to work with (tnx Sagi Isha) sent me this new library called Workflow (https://useworkflow.dev/) Its a small, elegant toolkit for orchestrating long-running operations (e.g sending emails, processing payments, etc) and make the logic more durable. Then another friend I showed it to asked - "What is this "use workflow" line doing? Isn’t it just a random string?", so its a great opportunity to talk about directives :) In JavaScript, one can put a bare string at the top of a file or function, and it becomes a #directive. The famous "use strict" works the same. These strings don’t run, don’t get printed, and don’t exist at runtime. They’re signals for the compiler / tooling. For example: "use strict" → tells the JS engine to switch to strict mode "use client" / "use server" → tells Next.js how to bundle "use workflow" → tells the Workflow engine: “This function is a workflow. Track it, persist it, resume it, and retry safely.” One can even create his own “directive” for a custom library. The string itself does nothing in JavaScript, but the tooling or runtime can detect it (for example via a build step, transpiler plugin, or a runtime wrapper) and then change the function’s behavior accordingly. It’s the same trick that powers "use workflow" or "use client", just applied in your own code. #JavaScript #WebDevelopment #CodingTips #Programming #DeveloperLife #JS #TechLearning #OpenSource #SoftwareEngineering

🚀 Ever wondered how JavaScript handles thousands of async tasks without breaking a sweat? Here’s the secret — it’s all about the Event Loop 🌀 While JavaScript runs on a single thread, it multitasks like a pro thanks to: ⚙️ Web APIs → handle async operations (like setTimeout, fetch) 🧩 Microtask Queue → high-priority tasks (like Promises) 🕓 Macrotask Queue → low-priority tasks (like timers, I/O) 🔁 Event Loop → keeps everything in sync, executing tasks in the right order Think of it like a comedy show — 🎤 The Call Stack performs the main act. ☕ The Microtask Queue (promises) impatiently waits backstage. 😴 The Macrotask Queue (timeouts) waits for its turn... maybe after a coffee break. So the magic order goes like this: 👉 synchronous → microtasks → macrotasks. That’s how JavaScript keeps running smoothly, even when your code looks chaotic! 💡 Fun fact: this entire process is powered by libuv (in Node.js), the hidden engine managing these background threads. 📘 Curious how Node.js handles I/O with threads and CPU cores? Stay tuned — I’m breaking that down next! 👇 #JavaScript #WebDevelopment #MERN #NodeJS #EventLoop #AsyncProgramming #FullStackDeveloper #Coding #Developers