[1] Kostiukovich/Ialin made their international debut in late September 2017 at the Junior Grand Prix (JGP) competition in Zagreb, Croatia, where they won the gold medal.

[4] In January 2018 Kostiukovich/Ialin won the bronze medal at the 2018 Russian Junior Championships after placing eleventh in the short program and second in the free skate.

They were part of a Russian sweep of the pairs' podium, along with their training partners Anastasia Mishina / Aleksandr Galliamov (bronze) and Daria Pavliuchenko / Denis Khodykin (gold).

They were ranked first in both the short program and the free skate and won the gold medal by a margin of more than 14 points over the silver medalist, their teammates Anastasia Poluianova / Dmitry Sopot.

They were ranked first in the short program and second in the free skate, and were beaten by the gold medalists, their teammates and training partners Kseniia Akhanteva / Valerii Kolesov by a margin of about 4 points.

They won the short program at Junior Worlds, narrowly ahead of both of the other Russian teams, and were awarded a gold small medal for the result.

(with Ialin) JGP: Junior Grand Prix Small medals for short and free programs awarded only at ISU Championships.