Sehyung (Sergey) Kim was born in 1987 in Almaty (Kazakhstan). He graduated from Vladislav Agafonnikov's composition class at the Moscow Conservatory and from 2013 to 2019 undertook his master's degree in composition at the University of Music and Performing Arts Graz with Beat Furrer, Pierluigi Billone and Bernhard Lang. From 2011 to 2012 he also received private composition lessons from Dmitri Kourliandski.

Sehyung has won numerous prizes in international competitions for his works, which range from solo compositions to music theatre, such as "DuoSolo" (USA, 2010), "Step to the Left" (Russia, 2012), "De la ville de Boulogne-Billancourt" (France, 2014), "Franz Schubert and Modern Music" (Austria, 2017), 7th Johann-Joseph-Fux Opera Composition Competition (Austria, 2018), and 5th Opera Composition Competition Neue Szene V (Germany, 2019). He participated several times in the International Summer Courses for New Music in Darmstadt (2010, 2014), the International Academy for Young Composers of the City of Tchaikovsky (2012, 2014, 2015), the 8th International Ensemble and Composer Academy for Contemporary Music "Impuls" In Graz (2013), and the 2nd Ukrainian Biennale for New Music in Kiev (2013).

In 2013 he was composer-in-residence of the GAM ensemble in Moscow. In the same year he was invited to a guest apprenticeship at the Kazakh National Conservatory in Almaty. In 2015 he was awarded the City of Graz Music Promotion Prize. In 2019 he received a two-year scholarship from the Deutsche Bank Foundation as part of the "Akademie Musiktheater heute". In 2020 he received “Startstipendium” scholarship from the Federal Chancellery of the Government of Austria. In 2021 he received Theodor von Körner Prize and State scholarship from the from the Austrian Federal Ministry for the Arts, Culture, Public Service and Sport

He received commissions from, among others, "Text im Klang" as part of the "Impuls" festival (2014), the International Summer Courses for New Music in Darmstadt (2014), the "International Music Bridge and Cultural Association Austria" (2016), and ORF and Jeunesse Austria (2017). In 2019 his chamber opera Consumnia was staged by Olivier Tambosi and directed by Wolfgang Hatting with the ensemble PPCM in Graz.

The ensembles that have performed his works include the Moscow Contemporary Music Ensemble (MCME), dissonArt, Klangforum Wien, Schallfeld Ensemble, ensemble PHACE, Ensemble Szene Instrumental, Batida, ensembleSpektrum, and Geori. He has worked with soloists such as Sergej Tchirkov, Valentin Garvie, Marco Blaauw, Krassimir Sterev and others.