Jan Koum (Ukrainian: ?? ???; born February 24, 1976) is a Ukrainian American computer programmer.
He is the co-founder and was the CEO of WhatsApp, a mobile messaging application which was acquired by Facebook Inc.
in February 2014 for US$19.3 billion.
In 2014, he entered the Forbes list of the 400 richest Americans at position 62, with an estimated worth of more than $7.5 billion.
He was the highest-ranked newcomer to the list that year.