Robert Grader Bringing over 35 years of international experience in the hospitality industry to this prominent business hotel in Warsaw, Grader, an Austrian national, is now overseeing the hotel’s launch of Marriott’s new mobile applications. Grader, who comes to the Warsaw Marriott after serving at the helm of Marriott Hotels in Stuttgart, Copenhagen, Heidelberg and Budapest, is now among Marriott hotel general managers across the world adding innovations to better meet the travel needs of guests.