Not sure that I would recommend actually hiring that guy. He does not seem to understand that modelling is only one part of the equation. If you model something non-trivial, usually you can not just hand over your R scripts to someone else and say: Please implement that in python/C. You have implementation constraints which feed back into the modelling itself, like latency or scalability. Furthermore, good luck in letting someone translate your non-trivial math into another language hoping that he won't break it in some subtle or non-subtle way. Its just far more efficient if you have someone who can actually do the prototype directly in python or C, and let then a pro-developer optimize specific parts of the code.