my guess is mysql , python and machine learning
I thought that Booze Allen’s Field Guide to Data Science did a thoughtful job of laying out at a very high level what skills to look for in a data scientist. Check out page 41 (well… 42 of the pdf) https://www.boozallen.com/content/dam/boozallen_site/sig/pdf/publications/2015-field-guide-to-data-science.pdf
The rest of the field guide is interesting too (or at least it was to me).
Apart from the technical know how, I think good communication skills are also required to be a good data scientist.
David Robinson does a great job of explaining the importance of written communication skills in his article - Advice to aspiring data scientists: start a blog.
Graphic designers don’t typically get evaluated based on bullet points on their CV or statements in a job interview: they share a portfolio with examples of their work. I think the data science field is shifting in the same direction: the easiest way to evaluate a candidate is to see a few examples of data analyses they’ve performed.
Blogging is an especially good fit for showing off your skills because, unlike a technical interview, you get to put your “best foot forward.”