Jan Koum

Jan Koum (Ukrainian: Ян Кум; born February 24, 1976) is a Ukrainian American entrepreneur and computer programmer. He is the co-founder and was the CEO of WhatsApp. 
Early life and career.
Koum was born in Kyiv, Ukraine. He was raised and grew up in Fastiv, outside Kyiv, and moved with his mother and grandmother to Mountain View, California.