By 2020, all written language will have been supplanted by emoji. But how did it come to this? To understand how emoji work, you first need to learn a little bit about Japanese cellphones in the late 90s, the mechanics of Unicode, and how computers render display fonts. With an understanding of how strange pieces of Japanese culture have become so deeply embedded in the way we communicate, you can start to use them in the things you build. Join CTO of Slack, Cal Henderson, as he shares how to use emoji for fun and for profit.