Sobolew drove his first World Cup race in Schukolowo in February 2007 , which he did not finish. He achieved his first international success at the Snowboard Junior World Championships 2009 in Nagano . There he finished fourth in the parallel giant slalom and won silver in the parallel slalom. At the Snowboard World Championships 2011 in La Molina he achieved 28th place in the parallel giant slalom and in the parallel slalom. In March 2011 in Moscow he reached eighth place, his first top ten placement in the World Cup. In the following season he took second place in the parallel slalom in Jauerling, his first and so far only World Cup finals. At the end of the season he won bronze in the parallel slalom and gold in the parallel giant slalom at the Russian Snowboard Championship 2012. At the 2013 Snowboard World Championships in Stoneham , he came 17th in the parallel giant slalom and 14th in the parallel slalom. At his first Olympic participation in Sochi in 2014 , he finished 27th in the parallel slalom and ninth in the parallel giant slalom. He finished the 2013/14 season in 15th place in the parallel ranking.
At the 2015 Snowboard World Championships on Kreischberg , Sobolew won silver in the parallel slalom and gold in the parallel giant slalom. In February 2015 he won his first World Cup victory in the parallel giant slalom in Sudelfeld . He finished the season in fifth place in the parallel slalom classification, fourth in the parallel world cup and third in the parallel giant slalom classification. After finishing third and first in the European Cup in Landgraaf and second in Hochfügen at the beginning of the 2015/16 season, he finished second in the parallel giant slalom in the World Cup in Carezza . This was followed by four top ten placements in the World Cup, including a victory in the parallel giant slalom in Rogla . At the end of the season he reached third place in the Parallel World Cup, second place in the overall ranking of the European Cup and first place in the Parallel Giant Slalom World Cup. At the end of March 2016 he became the Russian champion in the parallel giant slalom. He competed in the World Cup four times in the 2016/17 season. He won the parallel slalom in Cortina d'Ampezzo and finished second in the parallel giant slalom in Carezza . At the season highlight of the 2017 Snowboard World Championships in Sierra Nevada , he came in 33rd place in the parallel giant slalom and won the bronze medal in the parallel slalom. He finished the season on 11th place in the Parallel World Cup and eighth place in the Parallel Slalom World Cup. In the 2017/18 season he finished second in the parallel slalom in Bad Gastein and first in the parallel giant slalom in Carezza in the parallel slalom world cup, fifth in the parallel giant slalom world cup and fourth in the parallel world cup. At the season highlight, the 2018 Winter Olympics in Pyeongchang , he came 18th in the parallel giant slalom.
In the 2018/19 season he won in Moscow and Scuol . He also came second in Secret Garden Skiresort and won the Parallel World Cup at the end of the season. He finished fourth in the parallel giant slalom world cup and second in the parallel slalom world cup. The FIS Snowboard World Championships 2019 in Park City , he went to 13th place. The following season he won his seventh World Cup victory in Scuol and third place in the parallel giant slalom in Pyeongchang and Blue Mountain . He finished ninth in the Parallel Slalom World Cup and fourth in the Parallel World Cup and the Parallel Giant Slalom World Cup.
Sobolew has started in 99 world cup races so far. He achieved a top ten placement 38 times (as of the end of the 2019/20 season).
Russia
World cup
Sudelfeld
Rogla
Cortina d'Ampezzo
Scuol