37 articles tagged with ""javascript""
The event loop is Node.js's secret weapon — until you accidentally strangle it with synchronous code. Learn how it works and how to keep it spinning.
Your lodash merge call is silently letting attackers rewrite JavaScript's DNA. Prototype pollution is the vulnerability that breaks apps without touching a single line of YOUR code — and it's everywhere.
Node.js is single-threaded — until it isn't. Learn how Worker Threads let you run CPU-intensive tasks in parallel without choking the event loop that serves your users.
Every Express request passes through a chain of middleware functions before getting a response. Understanding how that chain works — and how to build your own — turns spaghetti apps into clean, maintainable systems.
You've heard of SQL injection and XSS, but prototype pollution is the sneaky JavaScript vulnerability that can turn a harmless object merge into a full app takeover. Let's break it down.
You're carefully validating user input, escaping output, using parameterized queries — and then a hacker manipulates Object.prototype and turns your entire app inside out. Prototype pollution is the JavaScript vulnerability most devs have never heard of, but attackers absolutely have.
Been writing raw SQL queries in your Node.js app? Or drowning in Sequelize boilerplate? Prisma is the ORM that made me feel at home coming from Laravel Eloquent — type-safe, auto-completed, and actually fun to use.
Your Express API crashes, your users see a wall of Node.js internals, and somewhere a hacker is taking notes. Let's fix error handling once and for all with centralized middleware, typed errors, and zero information leakage.
The event loop is single-threaded — and that's great, until you try to crunch numbers in it. Worker threads are Node's secret weapon for CPU-heavy tasks without tanking your server.
Your Node.js process started at 80MB and now it's sitting at 1.2GB after three days. No, it's not haunted — you have a memory leak. Let's find it and kill it.
You've heard of SQL injection, XSS, and CSRF. But have you met prototype pollution — the JavaScript attack that silently poisons every object in your app? Let's fix that.
Your npm package does a harmless-looking deep merge. An attacker sends one crafted JSON payload. Suddenly every object in your Node.js app has extra properties you never added — and your authentication logic starts returning true for everyone. Welcome to Prototype Pollution.
You're using Math.random() to generate password reset tokens. An attacker can predict the next value in about 30 seconds. Here's why 'random' doesn't mean 'secure' — and exactly how to fix it.
Imagine an attacker corrupting the DNA of every object in your Node.js app without writing a single exploit payload. That's prototype pollution. It's sneaky, widespread, and your dependencies are probably vulnerable right now.
Every time you SIGKILL your Node.js server, you're mid-conversation at a restaurant when the lights go out. Here's how to let your server finish what it started before dying with dignity.
Express gives you a blank canvas and infinite rope to hang yourself with. Coming from Laravel, I learned this the hard way when my 'quick' Node.js API turned into a 900-line app.js monster. Here's the structure I wish someone had shown me.
You know that feeling when userId shows up in a function parameter, then the caller, then the caller's caller, and suddenly it's req.user all the way down six layers? Node.js has had a fix for this since v16. Nobody told you.
Most developers treat streams like that one gym membership — they know it exists, they know it's good for them, but they never actually use it. Let's change that.
Memory leaks are like slow carbon monoxide poisoning for your Node.js server — silent, invisible, and deadly. Learn how to find them, fix them, and sleep better at night.
Node.js is single-threaded — until it isn't. Worker threads let you run CPU-heavy code in parallel without killing your server's responsiveness. Here's how to actually use them.
A single line like `obj[key] = value` can corrupt every object in your Node.js app. Prototype pollution is responsible for dozens of critical CVEs in libraries you're probably using right now — and most developers have never heard of it.
Your deployment restarts Node.js. 200 users mid-checkout get a connection reset. Their carts vanish. You are the villain. Here's how to not be the villain.
Your Node.js API is slow. Your boss is mad. You've added indexes, you've restarted the server, you've blamed the intern. Time to actually profile it.
If your production debugging strategy is `console.log('here')` followed by `console.log('here2')`, we need to talk. Structured logging in Node.js will save your sanity - and maybe your job.
Think you can just change your API endpoints whenever you want? Cool! Now explain to 10,000 mobile app users why their apps suddenly stopped working. Let's dive into API versioning strategies that keep everyone happy - old apps, new features, and your sanity!
Think try/catch is enough for error handling? Cool! Now explain why your Node.js server randomly crashes with 'unhandled promise rejection'. Let's dive into error handling patterns that actually work in production - from custom error classes to monitoring!
Think package-lock.json is just noise? Cool! Now explain why your app works locally but crashes in production. Let's dive into npm's lockfile, semantic versioning gotchas, and the dependency chaos you didn't know you had!
Think `npm install` is safe? Great! Now explain why your project has 1,247 dependencies and three different versions of lodash. Let's talk about npm best practices, dependency hell, and how to keep your node_modules folder from becoming sentient.
Think writing tests is boring busywork? Think TDD slows you down? Cool! Now explain why you spent 6 hours debugging a bug that tests would've caught in 30 seconds. Let's make Node.js testing fun and practical - you might even enjoy it!
Think try/catch is enough for Node.js error handling? Cool! Now explain why your server randomly crashes with 'unhandled promise rejection.' Let's dive into the error handling patterns that actually keep your API alive in production!
Think npm install is harmless? Cool! Now explain why your app broke after updating ONE package. Let's dive into dependency hell, security nightmares, and the package.json chaos that keeps Node.js developers up at night!
Think npm is just for installing packages? Cool! Now explain why you're writing bash scripts when npm can automate everything. Let's dive into npm scripts - the built-in task runner you didn't know you had!
Think console.log() is logging? Think try/catch fixes everything? Cool! Now explain why your Node.js server silently crashes at 3 AM with zero logs. Let's dive into error handling and logging that actually works in production!
Think your Node.js server is using all 8 CPU cores? Think again! By default, Node.js runs on ONE core while the other 7 watch Netflix. Let's fix that with cluster mode - the built-in feature that turns your server into a multi-core beast!
Think reading files with fs.readFile() is fine? Cool! Now explain why your Node.js server crashes when processing a 2GB file. Let's dive into streams - the memory-efficient pattern that saves your server from OOM crashes!
Think middleware is just app.use() and you're done? Cool! Now explain why your Express server randomly hangs. Let's dive into the middleware gotchas that bite every Node.js developer - from memory leaks to silent failures!
Think you understand async in Node.js? Great! Now explain why your API randomly hangs. Let's dive into the event loop, promises, and async patterns that actually work in production.