c++ Vertification

I'm looking to move from QA to Dev at my company, and my manager has agreed for me to do an online course and gain a certificate, then I can move into a Dev capactiy. He's mentioned the like of MIT and harvard online courses, but from my googling it seems these are opencourseware / EDx courses. I showed him c++ institute and their offerings, but he said that those certs aren't really worth much. Is there a defacto online course for C++ with certification that I should be looking at?​For info, I have a background in CS with experience in Java and Python, so intro courses aren't really of much benefit to me.​Thanks