In 1919, he worked as a court clerk in Bandung, before leaving that job to continue his legal education at Leiden University.

He obtained the title Doctor in de rechtsgeleerheid with a dissertation entitled De Mohamedaansche Vrome Stichtingen in Indië (Institute of Islamic Scholars in the Dutch East Indies), in which he outlined the law of war in the Dutch East Indies.

Upon his return to the Dutch East Indies, Kusumah Atmadja was offered a position as a judge at the Raad Van Justitie (High Court) in Batavia (now Jakarta) After a year, Kusumah Atmadja was appointed Landraad Voorzitter (Chairman of the District Court) in Indramayu.

[1] After Indonesia declared its independence on August 17, 1945, Atmaja was assigned to establish the country's Supreme Court in 1950.

[3] Prof. Dr. Raden Soelaiman Koesoemah Atmadja Effendi died on 11 August 1952, in Jakarta and was buried in Karet Bivak Cemetery.