TLDR: Badgen use [badgen](https://github.com/amio/badgen) to generate svg badges on the fly, running on Zeit's [now.sh](https://zeit.co/now), serving behind Now CDN.
The [badgen](https://github.com/amio/badgen) library was born as an exploration of "is it possible to generate badge svg markup directly with JavaScript(without using pdfkit/canvas/puppeteer to measure text length)?". Result is better than I expected, Verdana(the de-facto font for badges) text width can be calculated precisely with a prebuilt [char-width-table](https://github.com/amio/badgen/blob/master/lib/widths-verdana-11.json), even no need to worried about kerning 🤯
Then cames Badgen. I had a good time with [shields.io](https://shields.io)(and earlier [badge.fury.io](https://badge.fury.io)), but as time goes by Shields gets slower, leaves more and more broken badges in READMEs. Badgen is trying to be a fast alternative with simplicity and flexibility.
At beginning I was considering between [now.sh](https://zeit.co/now) and [Google Cloud Functions](https://cloud.google.com/functions/). Then Zeit released [Now CDN](https://zeit.co/blog/now-cdn) on the same day as [badgen.now.sh](https://badgen.now.sh)'s reveal, what a fate! Born to fall in love 😘. With Now CDN, Badgen removed all builtin cache while serving faster than ever. Now Badgen has settled it's home on Zeit's Now.