He is a very polyvalent skier. His debut in the World Cup is on December 15th, 2005, only 19 years old. After 3 years with some good placements, his boom happens in the season 2008-2009 when he arrives second in the Lake Louise downhill (starting with the number 65!) Then, in the Val D'Isére Giant Slalom his first victory arrives. After two months, again in Val D'Isére, he becomes the new World Champion in the Giant Slalom. One week later he wins the Crystal in the Super Combined.
During season 2009/10 Janka succeeded in conquering the overall World Cup and a gold medal in the giant slalom event in Vancouver 2010.
Winter Olympic Games
- 1 gold medal (Giant Slalom in 2010)
- 1 gold medal (Giant Slalom in 2009)
- 1 bronze medal (Downhill in 2009)
Juniores World Championship
- 1 bronze medal (Giant Slalom in 2006)
- Best placement in the overall ranking: 1° in 2010
- Winner of the Combined World Cup in 2009