Comment by kccqzy

The website you mention was, I believe, Google Foobar. Here's a nice article about it https://www.turing.com/kb/foobar-google-secret-hiring-techni... It was internally called Rabbit Hole. In true killed-by-Google fashion, they killed this recruiting tool too. It was formerly available at https://foobar.withgoogle.com/

They also used to have on-site versions of such programming contests. I've been to the one at their Los Angeles office twice. Very nice memories.