I lead a team of computer scientists in a French web company (SmartAdServer). We use machine learning and other mathematical tools in everyday life. Most problems we study do not have a solution out of the box, so we use unusual techniques very often, sometimes needing to adapt the classical ideas without a perfect theoretical ground but only empirical validation.
I first studied abstract mathematics (logics, set theory and model theory) and learnt many methods in applied mathematics for a few years. I still think more like a general mathematician than like a machine learning expert (that I'm not). I'm also a developer mainly interested in parallelism, low level optimization and performance: C++, C#, Java.
I try to focus truth and rigour mixed with practical intuition.