Oleg Šelajev is a developer advocate for the Graal project at Oracle Labs, which aims to make programs run faster and developers more productive. He helps to organize VirtualJUG, the online Java User Group, and a GDG chapter in Tartu, Estonia. In his spare time, he is pursuing a Ph.D. in dynamic system updates and code evolution. Previously, Oleg was a part-time lecturer at the University of Tartu and since then enjoys speaking, teaching, and participating in software conferences all over the world. In 2017 received a Java Champions title.