Which Skills Are Most Valuable In Machine Learning?

Knowing how to write high quality software -- the days of one team writing throwaway models and another team implementing them in production are slowly coming to an end. With programming languages like Python and R and their packages making it easy to work with data and models, it is reasonable to expect a data scientist or machine learning engineer to attain a high level of programming proficiency and understand the basics of system design. While "big data" is a term used way too often, it is true that the cost of data storage is on a dramatic downward trend. This means that there are more and more data sets from different domains to work with and apply models to. And yes, knowing something about at least one of the popular areas of the field that have gotten traction lately -- deep learning for computer vision and perception, recommendation engines, NLP -- would be a great thing once you have the fundamental understanding and technical proficiency.