Stephan was appointed as WPP’s first CTO in 2018. Before that he was UK Group CEO and Global CTO of Wunderman, having joined the company in 2016.

In 1999, he founded Acceleration, the leading marketing technology consulting firm. Acceleration joined WPP in 2012 and became a Wunderman division in 2016.

Stephan is a South African native and holds a master's degree in media and telecommunications law from Columbia Law School.