Roosseno Soerjohadikoesoemo

Three months after Roosseno's graduation, he founded an engineering firm along with his senior Sukarno who had recently been released from prison for political activities. Roosseno also took a job as a teaching assistant at THS. According to Sukarno's accounts, Roosseno often contributed to the firm's expenses from his supplementary income. Generally, in the firm Sukarno left the actual engineering calculations to Roosseno. The firm did not get much work, and only built a mosque and several houses in the Papandayan area. The firm was dissolved in 1933 when Sukarno was exiled to Ende.[4][5]

After the dissolution of the firm, Roosseno took on work as a civil engineer in Bandung's public works department, and later was also elected into Bandung's city council representing the Great Indonesia Party. He moved to Kediri in 1939, still working as a civil engineer for the local government.[4][5] According to Roosseno's accounts, shortly before the Japanese invasion of the Dutch East Indies he was ordered by the Dutch government to destroy some 150 bridges - and once the Japanese had seized Java, they ordered Roosseno to rebuild them.[6]

During the Japanese period, Roosseno was appointed as a professor at the reopened THS (called Bandung Kogyo Daigaku during the occupation).[5] He was also appointed into the advisory body Chuo Sangi-In, representing the Kediri region, and later also into the Investigating Committee for Preparatory Work for Independence.[7] Roosseno created and ran a "weapons laboratory" during the Indonesian National Revolution, which focused on sabotage of bridges in particular.[6]

As a member of the Great Indonesia Unity Party (PIR), Roosseno was appointed as a minister in the First Ali Sastroamidjojo Cabinet, initially as the Minister of Public Works.[8] He was reassigned as Minister of Communication following a cabinet reshuffle on 12 October 1953, and then resigned as part of PIR's temporary departure from the coalition on 23 October 1954. He later rejoined the cabinet as Minister of Economic Affairs on 8 November 1954.[9] As Economic Minister, Roosseno started a number of measures which tightened controls on foreign trade and banks.[10] Roosseno also chaired the Economic Committee of the Bandung Conference in 1955.[11]

During the Dutch period, Roosseno wrote a number of articles in the journal De Ingenieur in Ned. Indie, covering the use of reinforced concrete.[6] He went to France in 1955 to study prestressed concrete, which strongly inspired him. Roosseno planned a number of the most notable buildings in Jakarta, including Hotel Indonesia, the Istiqlal Mosque, and the National Monument (which was Roosseno's first use of prestressed concrete).[12] Due to Roosseno's extensive use of concrete in his designs, he was nicknamed "Indonesia's Father of Concrete".[1] Although Roosseno was close to Sukarno, he was largely unaffected by Sukarno's fall from power.[4] Roosseno remained as an engineering consultant, with his own firm in Jakarta, and perhaps Indonesia's best-respected civil engineer until near his death.[12][13]

In the research world, while Roosseno became a member of the executive board of the Indonesian Organization for Scientific Research in 1951 and 1953, he remained in private practice.[14] This was due to the low pay offered by academic institutions, and Roosseno only served as professor extraordinarius in Bandung.[15]