In June 2015, 16 year old Astashkina was selected to compete at the inaugural 2015 European Games in Baku, where she won four gold medals, in (200m, 100 m, 50m breaststroke), in 4 × 100 m medley (with Arina Openysheva, Polina Egorova and Maria Kameneva broke a new junior world record touching in at 4:03.22). Astashkina also broke a junior meet record in 200m breaststroke at the Games. On August 2–9, Astashkina competed in seniors at the 2015 World Championships in Kazan, however she did not reach the semifinals after losing in her preliminary heats.