There are two different things in your codebase both called time, and almost every date bug is the two of them being mistaken for each other. A ground-up model, in Go and Python.

An external API’s timestamps never matched our clock — and the gap kept growing. It was not one bug, it was two.

A creative roadmap for backend devs.

Everyone knows how to add a cache. Almost no one has a written-down invalidation strategy before shipping.

Most Go services start clean and turn into a tangle. Hexagonal architecture is the structural idea that keeps them untangled — here is how it works and how to apply it in Go.

Notes and highlights from reading Root Cause by Hussein Nasser — war stories from twenty years of backend bugs, and what each one taught.

The order you write a SQL query and the order the database executes it are completely different — and that gap explains most SQL mistakes.

You type a username. Before you finish, it’s already taken. No network call. No lag. How?

Cache stampede is when your own users become the attack. The fix is not more cache — it is treating the cache miss path like a critical section.