Maffei's first international appearance was at the Junior World Championships in 2001. Before that, she had already competed in the Viking Race Juniors in speed skating in 1998 in age group 13. Although she finished eighth there in Agnes Friesinger's victory , she decided on the short track sport. After she made it into the semi-finals over 1500 meters at two Junior World Championships there, the Italian Association also nominated her for the first time for the Short Track World Cup in October 2002 , where she finished third in the relay at her first World Cup start. She was also able to take part successfully in the Junior World Championships in 2003, but did not reach a final.
After Maffei made her first individual start in the 2003/2004 World Cup season, but started less successfully at the 2004 Junior World Cup, she did not contest any other international races in the 2004/05 season apart from the team world championship. In addition to the team championship, she also took part in the 2006 world championships , where she won the bronze medal with the relay. Because she competed in every 1500 m race in the 2006/07 Short Track World Cup , she was able to achieve seventh place in the 1500 m World Cup, even though she did not come in eleventh place as the best result. In sixth, she even barely missed the first single final of her World Cup career over 1000 meters. With the relay, on the other hand, she was able to celebrate her first World Cup victory in the Netherlands, but in the absence of some top nations and a starting field of only five relays. At the 2007 European Championships in Sheffield , she won the silver medal with the relay.
In the 2007/08 World Cup, Maffei was less successful, she did not achieve a single top 10 placement in the individual, and she also missed another win in the relay, even though she was able to take two second places. The Short Track World Cup 2008/09 began for Maffei with a tenth place over 1500 meters and thus achieved her best individual result of the season. With the season she was twice second and once third. Her best results at the 2010 Olympic Winter Games in Vancouver were 21st place over 1000 m and sixth place with the relay. She won the bronze medal at the 2010 team world championships in Bormio . In the 2010/11 season she won third place with the relay at the World Cup in Shanghai and Moscow . At the 2011 European Championships in Heerenveen , she won bronze with the relay. In the following season she won the World Cup in Nagoya with the relay and won the silver medal with the relay at the European Championships in Mladá Boleslav in 2012 . In the 2012/13 season she won third place with the relay in Shanghai and Sochi and in the 2013/14 season in Kolomna . At the 2014 World Championships in Montreal , Maffei won bronze in the relay. In February 2016 she won her third World Cup victory with the relay in Dresden . At the 2016 European Championships in Sochi, she won the bronze medal with the relay. In the 2016/17 season she was second with the relay at the World Cup in Dresden and Minsk . At the European Championships 2017 in Turin , she won gold with the relay. In November 2017, she came third in the relay at the World Cup in Shanghai.
Italy
Heerenveen 1
Nagoya 2
Dresden 3