Ruben Kozin was born in Moscow in 1997. When he was only 5 years old, he entered music school. At the age of 12, Ruben changed to the Central music school at the P.I. Tchaikovsky Moscow State Conservatory studying piano by Natalia Trull, professor of the Conservatory. In 2020 Ruben graduated from Moscow state P.I. Tchaikovsky Conservatory. 

In Russia Ruben Kozin has performed at the Great and the Small Rachmaninov Halls of The Moscow State Conservatory, at the Concert Hall of the Russian State Gnessin Academy of Music, the Moscow International House of Music and at the Concert Hall of the Moscow Museum of Musical Culture. Furthermore Ruben has given concerts in Croatia, Poland, Lithuania, Italy, Malta, Kazakhstan, Denmark, Germany, Belgium, Armenia and Belarus.

Ruben has already achieved a number of international competitions. In May 2016 he won the 3rd prize at the International Piano Competition FVG (Sacile, Italy), in September 2016 the 3rd prize at the Andre Dumortier International Piano Competition (Leuze-en-Hainaut, Belgium).