Castellucci studied political sciences, medieval and modern history and public law at the Universities of Heidelberg, Mannheim and at the San Francisco State University (SFSU) of California from 1995 to 2000, graduating with Magister Artium.

His dissertation explored possible courses of action for the labor market policy facing social outlawing in Germany.

Castellucci worked as project leader for community and regional development and public participation at IFOK GmbH from 2001 to 2013.

[7] Since 2014, Castelucci has also been serving on the Advisory Committee on Sinti and Roma at the Federal Ministry of the Interior.

In 2018, Castellucci campaigned to succeed Leni Breymaier as chair of the SPD in Baden-Württemberg; he eventually lost against his competitor Andreas Stoch.