Ross learned several skills related to golf throughout his life such as greens keeping, club making, golf pro, and architect. Ross got his first job at the Royal Dornoch Golf Club, where he played while growing up, working as a greens keeper. Ross served an apprenticeship with Old Tom Morris in St Andrews before investing his life savings in a trip to the U.S. After his year long apprenticeship he went back to the Royal Dornoch Golf Club where he honed his playing abilities while also taking care of the greens and making clubs. Later in 1899, with the encouragement and support of Harvard astronomy professor and Salem and Petersham, Massachusetts resident Robert W. Willson, he obtained his first job in America at Oakley Country Club in Watertown, Massachusetts. In 1900 he was appointed as the golf professional at the Pinehurst Resort in North Carolina, where he began his course design career and eventually designed four courses. He then began running a substantial practice with summer offices in Little Compton, Rhode Island. At its height, Donald J. Ross and Associates, as his practice was known, oversaw the work of thousands of people. However, Ross always kept up his professional golf standing. His brother Alec won the 1907 U.S. Open.