In 1993, at the age of 16, Szewczenko won her first international competition at the Nations Cup in Germany, defeating the reigning world champion Oksana Baiul. A few weeks later, she won her first national title, defeating former Olympic champion Katarina Witt. Szewczenko competed at the 1994 Winter Olympics in Lillehammer, Norway. During a practice session before the long program, she collided with Oksana Baiul, sustaining a bruised right hip and abdomen. She finished 6th at the event. Szewczenko won a bronze medal at the 1994 World Championships.

After finishing 6th at the 1996 Worlds, Szewczenko struggled for 18 months with a pair of viral infections which caused her to sleep 18 hours a day. She made a comeback in autumn 1997, winning on home ice at the 1997 Sparkassen Cup on Ice in Gelsenkirchen, Germany over eventual World champion, Irina Slutskaya. She went on to defeat former World champion Chen Lu and eventual World champion Maria Butyrskaya at the 1997 NHK Trophy in Nagano, Japan, and in doing so, earned a spot to the 1997–98 Champions Series Final in Munich, Germany. She won the silver medal behind American Tara Lipinski. Her tonsils were removed in December 1997.

Szewczenko posed for the German edition of Playboy magazine in April 1999 and March 2007. Beginning in 2002, she played the role of Katinka “Kati” Ritter on the German soap opera “Unter Uns.” Her last appearance on the soap was 5 December 2005. From September 2006 until 2009, Szewczenko appeared in the German soap opera “Alles was zählt” on RTL Television. She played the role of Diana Sommer, an inline courier, who trained as a figure skater alongside the wealthy daughter of a fitness center mogul. Norman Jeschke played her pair skating partner. In January 2009, Szewczenko left the series to return to show skating, joining the “Holiday On Ice” show with Jeschke.

Szewczenko retired from competitive figure skating in 2000 to concentrate on modelling and acting. She is the last German ladies’ singles skater to medal at an ISU Championships.