It started when I saw this Twitter thread about how QR codes work. (The above image comes from here – made by Dan Hollick.)

But that wasn’t enough. I needed more! Turns out they were invented in the 90s by Denso Wave, which is (or was?) a subsidiary of Toyota. They even have the invention story online.

The American Mathematical Society goes into even more detail.

Finally I found this incredible advanced article on animated QR codes that really blew my mind. Wow.

Just wanted to keep track of these links for later!