Niklas Zennström grew up in Uppsala, where he studied physics and economics at Uppsala University and then studied Civil Engineering. Niklas Zennström began his professional career in 1991 and worked for eight years in several companies of Jan Stenbeck and was employed by Tele2 and, for a period, also CEO of the Everyday.com portal.
Niklas Zennström and Janus Friis founded 2000 Kazaa, a file-sharing program based on P2P technology that two years later became the most downloaded software in the world. He and his partner continued to work together to create Skype, an IP telephone company that, in 2003, was bought by eBay in 2005 for $ 2.6 billion.
Zennström served as CEO of Skype until October 2007. During that time, Skype became the leading player in Internet-based voice communication (VoIP), with more than 309 million registered users and revenue of $ 551 million (2008 ). Together with Janus Friis, Zennström is also behind the Joost Internet video service and the Rdio online music service.
Niklas Zennström has founded and is CEO of the Atomico investment company, which invests in relatively new companies in the IT sector. The company wants to invest in fast-growing technology companies that have the conditions to change the market in which they operate. Atomico is based in London and offices in Beijing, Istanbul, São Paulo, and Tokyo. To date, Atomico has invested in more than 50 companies on four continents. Atomico's current and past investments include Rovio, Jawbone, FON, Fab, Klarna, and Skype.
In December 2013, Zennström was nominated by the H&M nominating committee for the H&M board. He is an active member of the Atomico venture capital company, which focuses on fast-growing technology companies. On November 27, 2014, Zennström was included in the SUP46 Swedish Startup Hall of Fame.
Niklas Zennström, together with his wife Cathrine, founded Zennström Philanthropies, which supports climate research, human rights, and entrepreneurship activities.