ted talkFacebook’s “like” and “share” buttons are seen 22 billion times a day, making them some of the most-viewed design elements ever created. Margaret Gould Stewart, Facebook’s director of product design, outlines three rules for design at such a massive scale—one so big that the tiniest of tweaks can cause global outrage, but also so large that the subtlest of improvements can positively impact the lives of many.

At Facebook (and previously at YouTube), Margaret Gould Stewart designs experiences that touch the lives of a large percentage of the world’s population.

View the Ted Talk video here