reccr was an automated video game recommendation service that I created from scratch in Ruby on Rails in late 2010.

It's like the "Movies You'll ♥" feature that Netflix used to have, but for video games; you rate the games you've played, and it compares your ratings to other peoples ratings to create sort of a personal "tastes profile" for you, and then uses that to suggest other games you'll enjoy.

The server it was on died in August 2012, and it was offline for a couple of years before I resurrected it in October of 2014, upgrading it from Rails 2.3 to Rails 4.1 in the process. It then continued to chug along until 2021.