Aleksey Kostenko completed his master and PhD studies in Donetsk National University (Ukraine) under the supervision of Professor Mark Malamud. During his postdoctoral career, he received several fellowships (ESI Junior Fellowship, IRCSET Fellowship and Lise-Meitner Fellowship). In 2012, he completed habilitation in the University of Vienna. Starting from 2013, Aleksey Kostenko is a principal investigator of several research projects funded by the Austrian Science Fund. Since 2017, AK is an Associated Professor at the Faculty of Mathematics and Physics, University of Ljubljana. For his work in spectral theory of linear operators in Hilbert spaces he received several awards including Ya. B. Lopatinskii award (2007) and Prize of the Austrian Mathematical Society (2016).