Severin Hacker, the Chief Technology Officer and Co-Founder of Duolingo , Inc. (NASDAQ:DUOL), recently sold a substantial portion of his holdings in the company. According to a filing with the ...
Duo was introduced in 2011. His green color was originally decided as a joke between co-founders Luis von Ahn and Severin Hacker, since it is Hacker's least favorite color, according to the ...