Jost began competing internationally with Roxane Petetin in the mid-1990s. They competed for three seasons on the ISU Junior Grand Prix series and placed 11th at the 2000 World Junior Championships. Petetin/Jost moved up to the senior level in the 2000–01 season. They last competed together at the 2004 European Championships, where they finished 12th. Petetin retired due to injury.