If this is something you'd like to do for twitter, and you have javascript, rails, and/or java/scala chops, or you're just a damn good generalist engineer who can pick up anything, send me an email at lzmfAuxjuufs/dpn.
We've historically had waaay more engineers than marketers on twitter's growth team. We look at growth less as marketing and more about optimizing (through ux, design, experiment, machine-learning, analytics, etc) all of our possible distribution channels with respect to a set of core metrics.
We lean towards teaching good generalist programmers how to do "growth," which actually doesn't feel much like marketing in day-to-day practice.
Also, why would someone who can program and market (like me) even want to work for twitter? Why not use my skills to make me (and not you) money?
These are not questions to be taken as an attack, but a real and hoest inquiry.