Backend Development, APIs & Deployment

Building APIs

gRPC vs REST: When Protocol Buffers Are Worth It gRPC is faster and strongly typed, but it needs a proxy to reach a browser and its errors are harder to read in a terminal. Here is when each one actually fits. Comparison · 8 min read · September 4, 2026
ECONNREFUSED: Why Node Can't Connect, and How to Fix It Nothing crashed in your code — the machine on the other end simply said no one's home. Here's what's actually happening on the wire, and how to fix it. Tutorial · 8 min read · September 2, 2026
Database Connection Pooling Explained A database connection is far more expensive to open than it looks. Here's what a pool actually buys you, and the one mistake that silently exhausts it. Tutorial · 8 min read · August 29, 2026
Prisma ORM Basics: Type-Safe Database Access for Node.js Prisma turns your database schema into a typed client, so a misspelled column fails at compile time instead of at 2am. Here is the setup and the traps beginners hit. Tutorial · 9 min read · August 24, 2026
Idempotency: Making It Safe to Retry A client sends a payment request and the connection times out. It does not know whether the payment happened. Whether retrying is safe is entirely determined by how you built the endpoint. Tutorial · 8 min read · August 22, 2026
API Authentication: Sessions, Tokens and Where to Store Them Every tutorial teaches JWTs and very few mention that you cannot easily log someone out. Choosing between sessions and tokens is a trade-off, and knowing which way it runs is the interesting part. Tutorial · 9 min read · August 21, 2026
Mongoose Basics: Adding a Schema to a Schemaless Database MongoDB lets you store anything, which is convenient right up to the moment a typo creates a second field name and half your queries quietly stop matching. Tutorial · 9 min read · August 18, 2026
Spring Boot for Students: Your First REST API in Java Spring has a reputation for configuration nightmares. Spring Boot exists specifically to remove that, and what remains is about six annotations you will use constantly. Tutorial · 9 min read · August 18, 2026
Building Your First API with Node and Express Express is small enough to understand completely in an afternoon, which is exactly why it is a good first backend. The parts people get wrong are the same four every time. Tutorial · 9 min read · August 17, 2026
Node Streams: Processing a 10 GB File on a 512 MB Server Reading a file into memory works until the file is bigger than your memory. Streams process it in pieces, and the memory difference is not subtle. Tutorial · 9 min read · August 16, 2026
OAuth Explained: What 'Sign in with Google' Is Actually Doing OAuth exists to answer one question: how do you let an app act on your behalf without handing it your password? The answer is a redirect dance that looks confusing and is genuinely elegant. Tutorial · 9 min read · August 13, 2026
Webhooks: Getting Told Instead of Asking Repeatedly Polling an API every ten seconds to ask whether a payment succeeded is wasteful and slow. A webhook reverses it: the other service calls you the moment something happens. Tutorial · 8 min read · August 13, 2026
Rate Limiting: Stopping One Client Taking Down Your API Without a rate limit, one buggy client in a retry loop can consume everything your API has. The algorithms are simple; choosing the right one depends on whether bursts are acceptable. Tutorial · 8 min read · August 13, 2026
Designing a REST API That Other People Can Actually Use A good API is one a developer can guess. That comes from consistency in a handful of decisions, most of which are made once and then repeated everywhere. Tutorial · 9 min read · August 13, 2026
API Versioning: Changing Things Without Breaking Everyone Once someone else depends on your API, you cannot change it freely. Versioning is how you keep moving without breaking the code you cannot see. Tutorial · 8 min read · August 13, 2026
API Testing With Postman: A Practical Guide The initial value of a Postman variable travels with the collection when you share it. The current value stays on your machine. Put your bearer token in the wrong box and you have just published it. Tutorial · 9 min read · August 6, 2026
Redis Caching Basics: Cache-Aside, TTL and Invalidation A cached object comes back from Redis as JSON, so the Date you put in is now a string. The code that worked yesterday throws on line one, and only for cache hits. Tutorial · 12 min read · August 6, 2026
WebSockets Explained: Handshake, Scaling and SSE Your chat app works perfectly until you run a second Node process behind a load balancer. Then half the messages never arrive, and nothing in the logs looks wrong. Tutorial · 12 min read · August 6, 2026
ESM vs CommonJS: import, require and the type Field Adding one line to package.json can break every require in your project at once. Here is what the two module systems actually are and where they refuse to meet. Comparison · 12 min read · August 6, 2026
Python JSON: load vs loads, and the Traps Between json.dumps on a datetime raises TypeError, and the default settings turn Hindi text into a wall of backslash-u escapes. Four functions, a handful of arguments, and a surprising number of ways to lose data. Tutorial · 10 min read · August 6, 2026
EADDRINUSE: Port Already in Use and How to Fix It The process holding port 3000 is almost always your own server from ten minutes ago. Killing it blindly is the wrong habit; finding it takes one command. Tutorial · 11 min read · August 6, 2026
SyntaxError: Unexpected Token and How to Locate It The line number in a SyntaxError is almost never the line with the mistake. And when the unexpected token is a less-than sign, your API returned an HTML error page. Tutorial · 11 min read · August 6, 2026
Module Not Found: Fixing Cannot Resolve Errors The import works on your Windows laptop and fails on the Linux deploy box. That is not a mystery; it is your filesystem quietly ignoring capital letters. Tutorial · 11 min read · August 6, 2026
Cannot GET /: Fixing Express Route Errors Cannot GET / is not an error at all. It is proof your server started perfectly and simply has no handler for that path, which means the fix is never in listen(). Tutorial · 11 min read · August 6, 2026
Unhandled Promise Rejection in Node: Causes and Fixes One missing await turns a try/catch into decoration. The block completes, the promise rejects a moment later, and modern Node responds by killing your server. Tutorial · 11 min read · August 6, 2026
Environment Variables Explained: Config Without Secrets in Code The first real security lesson most developers learn, usually the hard way — after committing an API key to a public repository. Tutorial · 10 min read · August 6, 2026
npm vs Yarn vs pnpm: Which Package Manager to Use All three install packages. The differences are speed, disk usage and how strictly they enforce your dependency tree — and mixing them causes real problems. Comparison · 9 min read · August 6, 2026
REST API Design: Practices That Make an API Usable An API is a user interface for developers. Most of what makes one pleasant is consistency, not cleverness. Tutorial · 11 min read · August 6, 2026
Backend Developer Roadmap: A Practical Order to Learn In Backend is less about frameworks than about data, correctness and failure. This is the order that builds those, rather than a list of logos. Career · 12 min read · August 6, 2026
How to Debug a 500 Internal Server Error A 500 tells you nothing except that the server failed. The logs tell you everything — and most people never look at them. Tutorial · 10 min read · August 6, 2026
npm Errors Explained: ERESOLVE, EACCES, ENOENT and More npm errors look alarming and are mostly four recurring problems. Knowing which one you have turns a lost afternoon into a two-minute fix. Tutorial · 10 min read · August 6, 2026
JWT Authentication Explained (and Where It Goes Wrong) A JWT is signed, not encrypted. Anyone holding one can read it — and confusing verify with decode is a complete authentication bypass. Tutorial · 11 min read · August 5, 2026
REST vs GraphQL: An Honest Comparison GraphQL solves a real problem that most projects do not have. Knowing which problem is the difference between a good choice and cargo cult. Comparison · 10 min read · August 5, 2026
HTTP Status Codes Explained: The Ones You Actually Meet The first digit tells you who has the problem. Getting 401 and 403 the wrong way round is the mistake almost every API makes at least once. Tutorial · 10 min read · August 5, 2026
What Is CORS and How to Fix the Error The request worked in Postman and fails in the browser. Nothing is broken — you are meeting a rule that only browsers enforce. Tutorial · 10 min read · August 5, 2026
JavaScript Fetch API Tutorial: Call APIs From the Browser A beginner-friendly guide to calling APIs from the browser with fetch: GET, POST, JSON, headers, error handling, and async/await, with working code. Tutorial · 9 min read · July 22, 2026
How to Build a REST API with Node.js and Express A beginner-friendly, step-by-step tutorial: build a small REST API in Express with working GET, POST, PUT and DELETE routes you can run and test yourself. Tutorial · 9 min read · July 22, 2026
What Is npm? Node Package Manager Explained A beginner-friendly guide to npm: what it does, how package.json and npm install work, and how to run npm scripts on your very first project. Tutorial · 9 min read · July 22, 2026
What is an API? A Simple Explanation for Beginners An API lets two programs talk to each other. Learn what that means with a simple waiter analogy, plus REST, JSON, status codes, and a real fetch() demo. Tutorial · 9 min read · July 22, 2026

Backend & APIs

Building APIs

Auth, sessions and security

Performance and scale

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