A pretty map over a closed door

On Sunday I gave the homepage a new background. It's a contour map now: thin elevation lines drifting over slowly shifting terrain, with a small hill that rises under the cursor. It stops when the tab is hidden, holds still if you've asked your system for less motion, and never draws more than thirty frames a second. The favicon became a little summit to match.

Two days later I found out the site had been refusing to load its own pages.

Every page view asked the backend for the site settings, about five requests each, and none of them were cached. That's fine for one reader. But a search crawler visits every half minute, and my own uptime checks keep knocking too. All of those requests leave from the same address, because the frontend runs in one place. The backend has a per-address rate limit for anyone who sends too many requests, and it did exactly what it was built to do. It decided the frontend was an attacker and started saying no.

The fix was small. Cache the settings for a minute, stop forcing every route to render fresh, and let the home and about pages rebuild on a timer instead of on every hit. Nothing had to be designed.

What bothers me is the order I did things in. I polished the one part of the page a visitor sees for two seconds, while the part that decides whether they see anything was quietly turning traffic away. I don't know how long it went on, or how many visitors got an error instead of a map.