Platonova competed with Andrei Maximishin from 2003 to 2007. They placed 6th at the 2005 World Junior Championships and 5th in 2006, as well as competing twice at the ISU Junior Grand Prix Final. Platonova and Maximishin placed 5th at 2006 Skate Canada International, their senior Grand Prix debut. They parted ways due to Platonova's back problem. They were coached by Alexei Gorshkov in Odintsovo.