As a junior Bay became 11 times junior national champion, won a gold and bronze medal in a ISU Junior World Cup Speed Skating race and participated at the 2009 and 2010 World Junior Speed Skating Championships. At elite level Bay represented Germany at international competitions. She competed at the 2011 World Single Distance Speed Skating Championships in the 1500 metres event (19th) and 3000 metres event (15th). At the European Speed Skating Championships she participated at the 2011 championships (15th overall), 2014 championships (15th overall) and 2015 championships (15th overall). She also competed at other international competitions, including at ISU Speed Skating World Cups.