efe-epaBy Antonio Torres del Cerro Sao Paulo

Frustrated with the red tape involved in opening a bank account in Brazil, Colombian entrepreneur David Velez decided to found his own fintech start-up, Nubank, in 2013.

Seven years later, it has grown to become one of the world's largest digital-only banks with 26 million customers and is valued at more than $1 billion.

Velez, who was born in Medellin on Oct. 2, 1981, and currently lives in Sao Paulo, has challenged Brazil's highly concentrated banking industry and now intends to do the same in Mexico, a market he says has many similarities.