I would argue that this is a "series of complex social tasks" -- Google Code-In is about having high school students get contributions to real open-source projects accepted. That means communicating over Slack/IRC/Mailing Lists, and learning each project's conventions, and so forth.

I remember taking part in this competition in high school, and I was only able to get one task done. And -- disclaimer -- I work for Google now.

By comparison, USACO or the Canadian Computing Competition is a walk in the park.