Summit Engineering of Santa Rosa has announced changes in its leadership team.

Yi Yang is now the managing principal, the firm announced. That role will make him responsible for the firm’s operations, business development and other strategic initiatives. According to the company website, Yang will also be a manager for the Structural Division.

He joined Summit in 2001 and received his bachelor’s degree in civil engineering from Case Western Reserve in Cleveland. In 2012, he was named one of the Business Journal’s Forty Under 40 winners.

Also, Greg Swaffar is now a principal with the firm. He previously served as president. And he remains involved in master-planning, permitting and project team leadership. He joined Summit in 1983 and is a graduate of the University of California, Davis.

Also announced as a new principal of the firm is Demae Rubins, manager of the Planning Division. Rubins joined Summit in 2006 and has more than 18 years of experience. She received a bachelor’s degree in landscape architecture at California Polytechnic University, San Luis Obispo.

Other leader-principals are Zak Zakalik, manager of the Electrical/Lighting Design Division; Jasper Lewis-Gehring, manager of the Civil Division; and Gina Giacone, manager of the Water/Waste Management Division.