Osmak won the Ukrainian Girl's Chess Championships several times in different age categories: U10 (2006, 2008), U12 (2010), U16 (2013), U20 (2012, 2013).

At the Ukrainian Women's Chess Championships, Osmak won gold (2017),[5] silver (2019) and four bronze (2014, 2015, 2018, 2020) medals.

In August 2021, Osmak won 2nd place in the European Individual Women's Chess Championship.

[7] Osmak represented the Ukrainian team in major team chess tournaments: Osmak was awarded the title of Woman Grandmaster (WGM) in 2016 by FIDE,[11] and in 2017 she achieved the title of International Master (IM).

The Fair Play Panel of the event say 20 players in total were disqualified but there is no sufficient "proof of actual cheating".