Jan Koum co-founded WhatsApp in 2009 after emigrating from Ukraine at 16, living on food stamps, and cleaning floors at a grocery store in San Jose — then sold it to Facebook for $19 billion in 2014 in one of the most celebrated startup exits in history. Born near Kyiv in 1976, Koum taught himself programming by reading discarded computer manuals and later worked as a security tester at Yahoo. WhatsApp grew to 450 million active users in just five years by obsessing over simplicity and reliability over monetization. Its commitment to privacy — no ads, no games, no gimmicks — was baked into Koum's personal experience of government surveillance growing up in Soviet Ukraine.
Reference:
TaskLoco™ — The Sticky Note GOAT
