58 articles tagged with ""backend""
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 users shouldn't stare at a spinner while you send a welcome email. Learn how to offload slow work to background jobs with BullMQ and Redis.
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.
You wouldn't fill a bathtub before washing your hands. So why are you loading a 2GB file into memory before sending it to a client? Node.js Streams are here to save your RAM — and your sanity.
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 unvalidated request is a ticking time bomb. Learn how to use Zod to add bulletproof, type-safe validation to your Express APIs — and sleep soundly at night.
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.
Ctrl+C your Node.js server and you might be dropping database connections, cutting off active requests, and losing in-flight jobs. Here's how to shut down like a professional instead of a villain.
Every time you change your API without versioning, a developer somewhere cries. Learn how to version your Express API properly so your users don't wake up to a broken integration at 3am.
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.
Without rate limiting, your API is an open bar with no last call. Learn how to implement rock-solid rate limiting in Express before one angry user (or bot) takes down your entire service.
You've been sprinkling console.log like parmesan on every bug. There's a built-in debugger in Node.js that's been sitting there this whole time, judging you.
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.
Changing ?user_id=123 to ?user_id=124 and suddenly seeing someone else's medical records. IDOR is OWASP's #1 vulnerability and it's embarrassingly simple — yet developers ship it every day. Let's fix that.
console.log is a lie you tell yourself in development. Here's how structured logging with Pino transforms your Node.js app from a black box into a system you can actually debug at 3am.
You added 'Login with Google' to your app and thought you were done with auth. Spoiler: you just opened 5 new attack vectors. Here's how OAuth 2.0 goes catastrophically wrong in production.
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.
Imagine visiting a cat meme site and accidentally transferring $5,000 from your bank account. That's CSRF — the sneaky attack where a malicious page hijacks your authenticated sessions to do terrible things on your behalf. Let's break it down!
Your server restarts 50 times a day, and every restart kills in-flight requests. Here's how to shut down gracefully so users never notice.
You built a beautiful API, deployed it proudly, and then someone just changed ?user_id=123 to ?user_id=124 and read your entire user database. IDOR is the vulnerability hiding in plain sight — and it's embarrassingly easy to miss.
Your API is probably sending 5-10x more data than it needs to. Learn how gzip and Brotli compression in Node.js can slash your bandwidth costs and make your app feel snappy — with three lines of code.
Webhooks are the backbone of modern integrations — but most devs get them wrong. Learn how to receive, verify, and process webhooks in Node.js without losing your mind (or your data).
Node.js is single-threaded — but your server has 8 cores. Learn how to use the cluster module to run multiple Node.js processes and actually use all that hardware you're paying for.
Every time your Express app opens a fresh database connection per request, a DBA somewhere cries. Learn how connection pooling works, why it matters, and how to configure it properly before your database gives up on you.
Insecure Direct Object References — the bug so simple it's embarrassing, yet so common it's in the OWASP Top 10. I once found my own app serving every user's private invoices to anyone who guessed a URL. Let me save you that call with your CEO.
Still hammering your server with HTTP requests every second to fake real-time? Let's fix that. Here's how WebSockets work in Node.js and why your users will thank you.
Node.js is single-threaded — until it isn't. Worker Threads let you run CPU-heavy code in parallel without spinning up new processes. Here's how to use them correctly.
You've seen the pattern: requestId threads through every function signature like a bad cold that just won't quit. AsyncLocalStorage fixes this elegantly — here's how.
That innocent-looking file upload button? It's one of the most dangerous features you can add to your app. Let's talk about how attackers upload webshells, bypass filters, and own your server — and how to stop them.
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.
Your webhook endpoint is wide open and anyone can POST fake events to it. Here's how to verify signatures in Node.js/Express so only legitimate providers can trigger your code.
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.
OFFSET pagination feels fine until page 500 brings your database to its knees. Here's how cursor-based pagination works, why it's faster, and how to implement it in Express.
Your Express API trusts whatever JSON the client sends. That's cute. Let's fix it with Zod — the schema validation library that'll save you from yourself.
Your string comparison looks innocent. It's actually a side-channel that lets attackers guess secrets one character at a time. Here's why constant-time comparison is non-negotiable.
Sending emails inside a request handler? Resizing images on the main thread? Let's talk about BullMQ — Redis-backed job queues that'll save your API response times and your sanity.
One flaky microservice shouldn't bring down your whole platform. The circuit breaker pattern is your safety net — here's how to implement it in Node.js and finally build resilient APIs.
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.
Without rate limiting, your API is an open bar with no closing time. Learn how to add the bouncer that keeps your server alive when traffic goes sideways.
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.
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 `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 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!
You just npm installed a package and gave a stranger root access to your machine. Congrats! After building Node.js apps in production, here's why your node_modules folder is scarier than any horror movie!
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.