On 16 September 2015, Buyalskyi made his UEFA Champions League debut in a 2–2 draw against Portuguese club Porto in the group stage.

[4] On 21 July 2018, Buyalskyi scored the only goal of the game as Dynamo defeated rivals Shakhtar Donetsk in the 2018 Ukrainian Super Cup.

[6][7] On 21 April 2021, Buyalskyi scored his first ever goal in the Ukrainian Cup as Dynamo defeated second division club Ahrobiznes Volochysk 3–0 in the semi-final.

[9] Buyalskyi was named in the 31-player senior national squad for the 2018 FIFA World Cup qualification match against Iceland on 5 September 2016.

[10] He made his debut on 6 October 2017 at Loro Boriçi Stadium in Shkodër, Albania, as a late substitute in Ukraine's 2–0 FIFA World Cup qualifying victory over Kosovo.