I think this might have something to do with the fact that he is the CTO of Durandal (which seems to be based off of durandal.io, or maybe the other way around).

I assume that he's currently the CTO of a very small company (of maybe even just him), and one of the ways to do that profitably, while building things you love, is to consult/provide training on the things that you have built that others want to use