Jan Koum (Messaging / Privacy Tech) at WhatsApp — Menlo Park, United States
Jan Koum co-founded WhatsApp with Brian Acton in 2009, building a messaging app with radical simplicity, no advertising, and strong privacy commitments. WhatsApp was acquired by Facebook for $19 billion in 2014 — the largest venture-backed acquisition at the time. Koum grew up in poverty in Ukraine and immigrated to the US at 16. He left Facebook's board in 2018 over privacy disagreements and has since invested in numerous tech companies.