Rakula was born in Germany in 1895 and was a machine gunner for the German Army in World War I. He lived in Berlin in the 1920s and 30s and was then employed by Rheinmetall and Steyr-Solothurn, where he would often correspond with colleague Fritz Herlach to design different firearms for both companies. He was also involved in the missile sector. Rakula would move to the United States some time after, eventually retiring to Philadelphia where he would die aged 65.
Rakula was known for designing the S1-100 submachine gun, adopted by the Austrian Army as the MP 34. He would also design the S18anti-tank rifle with colleague Fritz Herlach.