I accidentally broke one of my biggest sites because I used a CDN

Jul 9, 2020 technical a17t css wamr

I recently redesigned WhoAreMyRepresentatives with help from some Politiwatch volunteers. It’s just a simple flask app, and setting up some kind of asset pipeline for the CSS felt like overkill, so I imported a17t (my CSS library) from a CDN.

All was well until I released a new version of a17t a few days ago. (You can probably see where this is going.) Emails started to roll in about the site “being broken,” but because there weren’t that many reports and none of my uptime checks were failing, I assumed these were isolated incidents.

I was very wrong. Turns out that I imported the “latest” version of a17t from the CDN, so when I pushed the update, I accidentally broke nearly all of the CSS on the site. The thing was impossible to read.