BlaBlaCar is the world's largest international online marketplace for carpooling, founded by Mazzella together with Francis Nappez and Nicolas Brusson in 2008. In 2015, investors estimated BlaBlaCar's value at $1.6 billion, making it a so-called "unicorn", or startup with a capitalisation exceeding one billion dollars. BlaBlaCar operates in 22 countries and has 50 million users, more than 12 million of which are in the Russian market.
Frederic received a Master of Physics at the École Normale Supérieure in France. During his studies he interned in the Stanford Robotics Lab (Stanford University), and in 1999 also started the university's Master's programme in computer science.
In 2015, Mazzella was rated 49th in Wired 100, Wired magazine's list of the most influential people and organisations of Europe in high-tech.