Oleksandr Kryzhanovskyi graduated from the V. N. Karazin Kharkiv National University and has been working as a mathematics teacher at the Kharkiv Academic Lyceum #45 for more than 20 years. For his work he was awarded the title of "Honoured Teacher" and in 2010 he was named the winner of the All-Ukrainian "Teacher of the Year" competition in the field of mathematics.

Oleksandr is the founder and director of the Kobra Centre for Classical Education, which supports pupils in mathematics. Additionally, he is actively involved in mentoring mathematically talented children at the Fizmatik Education Centre in Kharkiv. Oleksandr has prepared numerous winners of All-Ukrainian and international olympiads and competitions in mathematics.     

Oleksandr is one of the founders and organizers of the All-Ukrainian Mathematics and Programming Summer School LOL, which has been held annually for 16 years. In 2023, the LOL Summer School will be organized online as the Kharkiv-Vienna Science School in cooperation with Project MmF.