[fevangelou]

So, if you read between the lines, React was basically built for a better "Like" button according to Dan's blog post here: https://overreacted.io/the-elements-of-ui-engineering/

Hmm...

[efdee]

React was written for Instagram. Nothing to do with Facebook's Like button.

[danabramov]

That’s inaccurate. React originally was extracted from the Ads codebase. (Complex forms for creating ads.)

Instagram was the first time it was used to drive the whole page (rather than a small widget).