One fact we're particularly proud of is that there are more people learning languages on Duolingo in the US than there are people learning languages in the entire US public school system.

I usually make to-do lists with timelines, and pen and paper does the trick for me.

The question that motivates my research is, if we can put a man on the Moon with 100,000 [people], what can we do with 100 million?

My ultimate research goal is to transform our human existence to just eating, sleeping, drinking, playing - nevermind.

People are good at figuring out what's attractive, and computers are good at quickly searching and finding. You put them together, and bang!

Every time you buy tickets on Ticketmaster, you help to digitize a book.

This sounds strange to many people, but I work out for exactly 16 minutes every day, and do so at maximum speed by running 2.5 miles. This keeps me healthy without taking up too much time so I can stay focused on other things. It's one of the most efficient things I do each day.