Matheas is an external counsel of MAGNUS. He is Tax Consultant and certified Tax Lawyer (BKP), having 15 years of experience and practical knowledge and has handled over a hundred tax related cases, both for individuals and corporations. He is an expert and experienced in handling tax disputes, both from disputes at the Tax Service Office and at the Tax Court. In his practice, he strongly adheres to the professional code of ethics in practice.

Apart from his practice as a Tax Consultant, he is also a lecturer at several universities in Yogyakarta. Further, he is also an active speaker for various tax and accounting trainings and seminars, including tax training organized by the Indonesian Tax Consultants Association (IKPI), the Indonesian Institute of Certified Public Accountants (IAPI), and the Indonesian Institute of Accountants (IAI).