A founder-CEO of the Sial Engenharia construction firm out of Curitiba, Arnaldi’s main interest is civil construction. In the 1990s, he bought a small construction company, Sial Construções Civis. He was head of the Western Paraná Construction Industry Union from 2000 to 2001. Then he became chairman of State Chamber of Civil Construction out of Curitiba from 2003 to 2004. As State Treasurer of the Social Democratic Party, he was in this role at Paraná in 2012 and 2013 as a candidate for the Federal Deputy of the State of Paraná in 2018, having earned 35,000 votes. 

His business interest in construction has served him his whole life, and he started Sial with two other partners in an engineering company, which provided service to other construction companies using cement management technology. Construtora Sial was a minor venture he started in the 1990s. He tries to have intensive communication with his employees, because they all work together to assess solutions as applied to their goals and problems faced in any given moment. He has lunch at home daily, followed up by studies of medium-to-long term projects. He studies new ideas carefully in order to see how they can be brought about to come to life. Arnaldi believes in comparing what went wrong to what went well. He runs his team focusing on a single objective. His advice to his younger self is don’t stress, read, travel, study, and focus on your unique view of real estate as it is now. His main partner is Technical Director Armando Hiroshe whom he works closely with to transform Brazil’s construction community. Arndali has wholehearted belief in dedication to one’s goals, which means to focus on what needs to done overall along with building yourself a great team who works together with unsurpassed loyalty and drive.