In 2015, Naidin competed at the international junior gymnastics competition, the Yokohama Cup in Japan finishing 4th in horizontal bar and 5th on floor.

In 2016, Naidin won the 2016 Russian Junior National all-around title, he also took first place in floor, rings and pommel horse.

On July 23–30, he competed at the 2017 European Youth Olympic Festival in Győr, Hungary where team Russia won gold (together with Yuri Busse and Aleksandr Kartsev).

He finished 6th in the all-around and qualified to three apparatus finals, winning two gold medals in parallel bars and pommel horse, and bronze in rings.

In 2018, Naidin competed for the qualifying competition in artistic gymnastics for the 2018 Summer Youth Olympics held in Baku, Azerbaijan, where he took silver in the all-around behind teammate Yuri Busse.