Career
Marczyński previously competed for Ceramica Flaminia–Bossini Docce between 2006 and 2008, Miche–Silver Cross–Selle Italia in 2009, Commodity Credit Corporation–Polsat–Polkowice in 2010 and 2011, and Vacansoleil–Distinguished Conduct Medal in 2012 and 2013. Marczyński was born in Krakow, Poland, and he started as a trainee for the Krakus Swoszowice team, staying with them from 1998–2002, and then riding for Pacyfik Toruń from 2003–2005. In 2006 he began a professional career with the Italian team Ceramica Flaminia–Bossini Docce.
In September 2015 it was reported that Marczyński would join Lotto–Soudal for the 2016 season, returning to the WorldTour ranks for the first time since 2013.