Rosinus Partner is a trusted port of call for all aspects of preventive compliance. The practice is led by Christian Rosinus, who handles complex, ongoing mandates at the intersection of compliance and white-collar criminal law, alongside Mathias Grzesiek, who specialises in preventive compliance and cybersecurity. Mirjam Steinfeld, elevated to the equity partnership in July 2025, also advises on preventive compliance and internal reporting structures. Arthur Leonhardt, who joined the team in April 2025, focuses on ombudsperson matters, while Janina Brandau departed in March 2025 to join the tax authorities.
Legal 500 Editorial commentary
Accolades
Client satisfaction: Lawyer & team quality
Testimonials
Collated independently by Legal 500 research team.
- 'Christian Rosinus and his team are an excellent, responsive group of people who really know the topic. They have a can-do attitude and deliver clear, pragmatic advice which sets them apart.'
- 'Christian Rosinus exudes calm in the most difficult situations. He is unflappable.'
- 'Christian Rosinus is an exceptional lawyer, brilliant mind, creative, but practical and easy to implement. Happy he is not on the other side!'
- 'Small boutique firm which delivers discreet, smart, and practical advice on the highest legal expert level. We are happy to have them as our advisers.'
- 'A competent contact person is always available to you within a very short time.'
- 'Very pragmatic and solution-oriented. Always approachable and full of useful ideas and suggestions.'
- 'A unique team of experts who are very personable and flexibly respond to our needs. The professional competence of this company is very high.'
- 'All the company's employees with whom we have worked so far are characterized by a high level of expertise. Furthermore, the collaboration is always very friendly and constructive. Regardless of when we contact them, we receive a very quick or immediate response, and our inquiries are processed immediately.'
Key clients
- Battenfeld Cincennatti
- GEW Wilhelmshaven, Bosch-Magura, etc.
- VDE e.V.
Work highlights
Provided comprehensive compliance support to numerous internationally active companies in the plastics industry on compliance.
Provided compliance support involving high-risk exposure and regulatory monitoring to financial institutions and insurance companies.
Lawyers
Next Generation Partners
Junior partners with significant recognition from clients and peers in the market and key roles on multiple matters.
Christian Rosinus
Practice head
Christian Rosinus; Mathias Grzesiek; Mirjam Steinfeld
Other key lawyers
Arthur Leonhardt