Melan wrote his habilitation thesis on the theory of bridges and railways at the same university in 1880 and remained on the teaching staff there until 1886.
It was during this period that he also worked in the design offices of the Ignaz Gridl bridge-building company and for the building contractor Gaertner – both based in Vienna.
He was head of the Chair of Bridge-Building at the Deutsche Technische Hochschule Prag (founded 1717) in Prague from 1902 until his transfer to emeritus status in 1923.
The Melan System, which links steel and concrete construction, won significant market-shares in European and American bridge-building as early as the 1890s and was awarded a gold medal at the World Exposition in Paris in 1900.
For example, in 1913 the American bridge-builder David B. Steinman translated Melan's theory of arch and suspension bridges.