What thirty seconds of checking would have caught
A catalogue of small, boring, real failures — a www that resolves nowhere, a redirect that drops to http, a response that is not actually compressed — each one cheap to see from outside.
SEO
Everything in The Nest tagged SEO.
Nothing fails when a page gets heavier
Generated markup is verbose, imports whole libraries for one function, and inlines assets because that works. Every test still passes. The cost lands on a phone on a slow connection, months later, as a number with no cause attached.
Staging configuration travels, and agents help it
A canonical tag pointing at staging, a noindex that shipped, a test API key in production. Each is invisible on a developer's machine and expensive live, and copying config between environments is the fastest way to make something work.
Four hops to nowhere: what refactors do to your redirects
Every restructure moves URLs, and every move adds a redirect. Nobody ever removes one. The result is a chain a crawler stops following and a browser spends a second on before it sees a single byte of content.
Reading a site the way a machine does
Your browser smooths over a great deal of what your site actually sends. Here are the terminal commands that show you what a crawler, a link checker or a monitoring probe gets instead.
Your agent built a single-page app and the AI crawlers see an empty div
Ask an agent for a website and you will usually get a client-rendered one. The AI crawlers largely do not execute JavaScript, so what they store is an empty div — and one curl command will tell you whether that is your page.