In 1906 Ros graduated from the Royal Technical University of Hanover with a degree in civil engineering, specializing in bridge construction. This was followed by work as a bridge engineer for the Gotthard Railway in Switzerland from 1906 to 1907. In his professional career, Ros laid the foundation for an academic career that began in 1923 with a lectureship in steel construction at the Swiss Federal Institute of Technology (ETH) in Zurich.
He was appointed professor in the same year. A year later, he was appointed director of the then Swiss Federal Materials Testing Institute at the ETH Zurich.
Ros played a major role in the development of experimental materials research and in the expansion of technological mechanics and materials research based on the fundamentals of structural analysis and strength theory. According to Ros, systematic experiment in materials testing should be as close as possible to reality, but not as a direct imitation, but as a synthesis between theory and practice.