Hoffmann, who started for the WSC Bayer Dormagen , won the title in the two-man canoe with Tim Welsink and the team title at the 1997 German Schoolchildren's Championships. He was also 19th in a single kayak . In the following year he started again at the school championships and repeated the victories in the two-man canoe and with the team. Instead of a single kayak, this time he started as the third race in a single canoe , where he secured silver. Until 2000 he started at the German Youth Championships and won his first and only title in this age group after two bronze medals in 1999. In 2002 he won the German Junior Championship in single canoe. Thereupon he started in the adults for the first time in the same year and immediately finished fifth at the German championships. At the Junior World Championships in 2002 he won bronze in singles and silver with the team. A year later, Hoffmann won silver in singles and bronze with the team at the German championships. He finished his first season in the Canoe Slalom World Cup in 2003 as 58th overall. In 2004 he won the single canoe title with the team at the U23 European Championships. In the individual competition, he secured silver. He was unable to repeat the individual success in the following years. Only with the team it was enough to bronze in 2006 and silver in 2007. In the 2007 World Cup he reached 33rd place overall, before winning silver with the team at the 2007 Canoe Slalom World Championships in Foz do Iguaçu . In the individual competition, he finished the competition in 21st place. The following year he won the bronze medal at the Canoe Slalom European Championships in Krakow with the single-canoe team . A little later he finished his most successful World Cup season as 25th overall. At the 2009 World Championships, he remained without a medal in both individual and team competitions. After the 2010 World Cup season, in which he was only 65th overall, he ended his active career.