Johan is an experienced litigator at all levels of the Dutch court system. He is admitted to the Supreme Court bar. Next to his Supreme Court litigation practice, Johan focuses on mass claims and complex cross-border disputes. He advises Dutch and international organisations and corporations on all matters of contract and consumer law, including green claims.

Johan contributes to the two most authoritative Dutch civil law commentaries and regularly publishes in academic journals. He is editor of the Dutch law journal on property, contract and tort law.