The code that powered One Million Checkboxes
I have made no attempt to clean up this code. My git hygiene was really bad. At many points I wrote awful hacky code. Sorry.
If you're interested in reading this code, I recommend that you begin with the code as it existed when I launched the site and then observe how it evolved over time. I think that's a much better way of learning what I did than simply looking at the end result. There are a lot of problems with the end result! It's not good code.
See this blog post for some details on the changes that I made to the site to scale it up.
The data from One Million Checkboxes is available on the internet archive. And a separate repo of mine provides scripts for working with the data.
It was really special to get to run this site. Thanks for playing :)