Deputat's mother, a recreational skater, introduced him to skating at age two years and eight months. He switched from singles to pair skating at age 15 and competed for two seasons with Vladyslava Rybka. They represented Ukraine and were coached by Galina Kukhar in Kiev. In the summer of 2009, they spent some time training in Ashburn, Virginia with Rashid Kadyrkaev and competed at the Liberty Summer Competition in Aston, Pennsylvania where they won the silver medal. They were ineligible for the 2009–10 ISU Junior Grand Prix series because Rybka turned 12 at the end of July 2009 and they parted ways soon after. Unable to find him a suitable partner in Ukraine, Kukhar recommended that Deputat move to Moscow. Arriving in Russia in early 2010, Deputat joined Sergei Dobroskokov's group and had a brief partnership with Polina Safronova.
Partnership with Davankova
Deputat and Vasilisa Davankova skated in the same group before teaming up in May 2011.
2011–12 season
In December 2011, Davankova/Deputat competed on the senior level at the 2012 Russian Championships. They were seventh in the short program but finished fifth overall, receiving the highest TES in the free skate ahead of the gold medalists Vera Bazarova / Yuri Larionov. In February 2012, they won the gold medal at the 2012 Russian Junior Championships after placing first in both the short and free segments. Deputat was released by Ukraine to represent Russia. Davankova/Deputat won the bronze medal in their international debut at the 2012 World Junior Championships.
2012–13 season
Davankova/Deputat won silver at their first JGP event in Lake Placid, New York. At their second event, in Zagreb, Croatia, they took the bronze and qualified for the JGP Final in Sochi, Russia, where they won the silver medal behind Lina Fedorova / Maxim Miroshkin. By that time, Davankova had grown to 1.55 m. Davankova/Deputat finished seventh in their second appearance at the 2013 Russian Championships. In January 2013, Davankova injured her leg at a training session, resulting in the pair withdrawing from the 2013 Russian Junior Championships. She was on crutches for two weeks. In late March, Deputat injured his right leg and decided to undergo a meniscus operation.
2013–14 season
Davankova/Deputat began their season by winning bronze at the 2013 JGP Belarus. A silver medal at the 2013 JGP Estonia qualified them to the JGP Final in Fukuoka, Japan. At the final, Davankova/Deputat placed fifth in both segments and overall. At the Russian Championships, the pair finished fifth on the senior level and then won the bronze medal on the junior level. Davankova/Deputat were assigned to the 2014 World Junior Championships in Sofia, Bulgaria, where they finished fourth after placing third in the short program and fifth in the free skate. Their partnership ended because Deputat was struggling with elements as Davankova grew taller.