In the year 2000 founded Hoteles.com, one of the leading hotel reservation sites targeting Spanish speaking users around the world, now owned and operated by Expedia. In 2003 he co-founded and led as CEO ClickDiario Network, at the time, the #1 Internet advertising network in Latin America, acquired by FOX International Channels (Newscorp) in 2006. From 2008 to 2011, de Tezanos led BrokersWeb as CEO, an online insurance marketplace in the United States, which became the 20th fastest growing company in the US in the INC 500 ranking of 2011.

Matias de Tezanos was Honored Young Global Leader by the WEF in 2009 and named one of the top 10 Hispanic entrepreneurs by INC Magazine during 2011 and 2012.

In 2012, founded PeopleFund, a private holding company that invests in tech-startups around the world, including several top INC 500 ranked companies like Healthcare.com, AutoWeb.com (merged with Nasdaq: ABTL), DiamondFoundry, Orionis Biosciences, GetAround, Bluekite (Acquired by Nasdaq: Xoom), among 30+ other companies and social impact projects like KingoEnergy.