Sky Wikluh, popular Serbian composer and rap musician, wrote a song for her, named "Moja noć", with production done by Gru. This song was one of the reserves for the Beovizija 2009, if someone of twenty contestants decided not to take part in. Kostić also sang as backing vocal for Regina's song "Bistra voda", which represented Bosnia and Herzegovina in the Eurovision Song Contest 2009. On 1 July 2009 Kostić performed "Bože pravde", the anthem of Serbia, alongside two more singers at the opening ceremony of 2009 Summer Universiade, which was held in Belgrade. She also performed "Bože pravde" at the closing ceremony of the 2009 Summer Universiade, and at the public reception of Serbian champions from the 2009 World Aquatics Championships. In August 2009, Kostić performed as a revival artist at the music festival in Ohrid, performing "Moja noć" and her new single "Daj mi sve", which features Sky Wikluh as a supporting artist.