Career
Born in Vilnius, Šiškevičius has competed as a professional since the start of the 2011 season, as the Louisiana Pomme Marseille team he had been a member successfully became a Continental team Šiškevičius left Louisiana Pomme Marseille at the end of the 2012 season, and joined Sojasun for the 2013 season. Šiškevičius returned to Team Louisiana Pomme Marseille 13 for the 2014 season, after Sojasun folded at the end of 2013.