9 articles
Your API is running the same database query hundreds of times a minute. Redis caching fixes that — response times drop from 400ms to under 10ms. Here's the complete setup: client config, cache-aside pattern, per-user keys, cache invalidation, and a reusable Express middleware.
No rate limiting means any client can hit your API as many times as it wants. This guide walks through the right way to implement it in Node.js - from express-rate-limit basics to Redis-backed sliding windows and layered per-route limits that work in production.
Most developers think session hijacking is an advanced attack. It's not. It usually starts with something very basic: your cookies. Learn the 3 flags and token refresh pattern that actually works.
ERR_REQUIRE_ESM. Missing extensions. No __dirname. The ESM/CJS war is still breaking Node.js projects in 2026. Here's the root cause, all five errors you'll hit, and the exact fixes for each one.
A slow MongoDB + Node.js API was taking 15 minutes to return 8,000 records. Here's the exact process I used to diagnose it — missing indexes, in-memory aggregation, no pagination — and bring it down to 15 seconds.
You split your backend into separate repos. Now you have twelve repos, nine package.json files with slightly different dependency versions, four copies of your validation utils, and six CI pipelines to coordinate for one feature. Here's the monorepo setup that actually works.
You changed assert to with and everything worked again — but you have no idea why the syntax changed, whether it's safe to use, or what happens in environments that still expect assert. Here's the full story, the exact migration, and every edge case that will trip you up.
Your Node.js server runs fine for days. Then memory climbs past 800MB, then 1.2GB, then the process restarts. That's not a capacity problem — that's a memory leak. Here's how to find it before it finds you.
Bad auth doesn't announce itself. Here's how Slack, Netflix, GitHub, and Stripe solved JWT and role-based access — and what you can steal from them.
