Andreas Rittstieg worked as a lawyer from 1984 to 2014. After positions with notable law firms in Los Angeles and Tokyo, he joined the Hamburg firm Stegemann, Sieveking & Lutteroth (now Freshfields Bruckhaus Deringer) in 1987 as an associate, specialising in transaction consulting under company law. In his own law firm Rittstieg Rechtsanwälte, which he founded in 2000 and which became part of the supra-local law firm Gleiss Lutz in 2010, he also focused on consulting for company transactions. He has also acted as arbitrator for a range of company law disputes and served on the supervisory boards of listed and privately held companies. He has been a board member at Hubert Burda Media since 2014 and is responsible for Legal and Compliance.