CS would give you the most bang-for-your-buck, especially a program that can let you specialize in machine learning. You may be able to leverage your software

CS would give you the most bang-for-your-buck, especially a program that can let you specialize in machine learning. You may be able to leverage your software engineering positions to skip an additional degree. I've heard people argue that data scientists are software engineers with additional specialized knowledge, which I think is largely true.