Mariusz Gralewski is a Co-Founder and serves as Chief Executive Officer at ZnanyLekarz. He also serves as an Executive at Protos Venture Capital. He serves as a Board member at Preply. While still a student, he founded GoldenLine.pl - the biggest social network for professionals in Poland. He holds degree in Electronics from Warsaw University of Technology. Gralewskiego is the Founder and serves as Chief Executive Officer at GoldenLine. He is an Advisor of PushPushGo.