Ustym studied at the Lviv Special Music School S. Krushelnytska with O. Bodnar and D. Komonko and continued his studies at the Lviv National Music Academy M. Lysenko receiving a Master degree.
He served as principal of viola section in the ”Academia” orchestra (Lviv), “INSO - Lviv” orchestra, Kyiv Chamber Orchestra conducted by R. Koffman (Kyiv), and the Chamber orchestra “Lemberg Simfonietta”. He teaches at the Lviv Special Music School S. Krushelnytska.
2010 - participated in Masterclasses (Holand) headed by «Szymanowski Quartet» (Hannover, Germany) and «Jerusalem Quartet». Founder of “Phoenix” string quartet (Lviv).
He has toured with famous musicians A. Belov, N. Khoma, V. Vynnytskiy, A. Brendel, R. Koffman, S. Sondetskis. Since 202, he has played principal of viola section in the Academic Symphony Orchestra of Lviv National Music Philharmonic and Principal Viola of the New Era Orchestra (Kyiv).
He has had solo performances with the Chamber orchestra “Lviv Virtuosos”, Academic Symphony Orchestra of Lviv National Music Philarmonie, the Chamber orchestra
“Trembita”, the Chamber Orchestra “Academia”, the Academic Symphony Orchestra of Chernivetska Philarmony, and the Chamber orchestra in Dolniy Kubin (Slovakia).
He is a Laureate of the II prize of the All-Ukrainian competition of performers on stringed instruments (Lviv) in 2003, the Winner of the First Prize of the 8th International Bohdan Varshal Competition (Slovakia) in 2004, Laureate of the First Prize of the International Viola Competition named after Zenon Dashak (Kyiv) 2004, Winner of the 1st prize of the 9th Bohdan Varshal International Competition, chamber play category (Slovakia) 2005, Laureate of the First Prize of the All-Ukrainian Competition of Violinists and Cellists (Lviv) 2008, and Laureate of the First Prize of the All-Ukrainian Competition of Chamber Ensembles and Quartets (Lviv) 2009.