Once again Molinos Río de la Plata S.A. trusted us for a new project. In this case we help them in the redisign of a online trading tool, used by the company for managing beans transactions with its clients. In order to accomplish the objectives planned, we developed a user-centred methodology that involved usability testing and paper prototyping. As part of our research process, we had the opportunity to make a visit to the plant from which the company exports and produces products, as well as the Rosario Commodities Exchange building.