Programming

Write-ahead logging is the technique PostgreSQL, SQLite, and MySQL use to avoid losing a single write during a power outage. This article explains how the change log works, how to enable and verify it, and when it’s better to avoid it.

CQRS separates the model that writes data from the model that reads it, each optimized for its own task. This guide explains how it works, when it makes sense, and when it doesn’t, with progressive code examples and diagrams of the full flow.

Rsync syncs files without retransmitting them in full, thanks to a block-signature algorithm and rolling checksums. Learn how it works under the hood, with code examples and when to use it over alternatives like scp or Borg.

Cache-Control and ETag are the two headers that decide whether the browser reuses a response or asks for it again. This guide explains each directive with real code, a diagram of the cache hierarchy, and the mistakes that most often break production.

Database sharding splits a giant table into independent fragments that live on separate servers. This guide explains hash, range, and directory-based strategies, with examples in PostgreSQL and application code.

A Service Worker is a script the browser runs in the background, separate from the page, that can intercept every network request. Thanks to it, a web app can keep working offline, show cached content instantly, and even receive push notifications. This guide explains its full lifecycle and the caching strategies PWAs use in production.