The prime focus of Jens-Holger Petri's work is on outsourcing and IT projects, particularly within the financial sector. He is a trusted advisor in both contract negotiation and project implementation, e. g. in contentious situations. He also specialises in matters of data protection and banking supervision as well as IT public procurement law.

A particular strength of Jens-Holger Petri is the legal support of projects on special topics such as core banking systems, trading systems, card processing, payment systems, digital assets (crypto), FinTech, banking as a service or Industry 4.0.