Yes, that's what I do too. "Service" modules contain all the functions, with all dependencies explicitly passed into them, and at the bottom of the module is a

Yes, that's what I do too. "Service" modules contain all the functions, with all dependencies explicitly passed into them, and at the bottom of the module is an interface with the dependencies assumed injected and a factory function that takes all the dependencies and returns an object with that interface. In general I use a suave functional styled api on the top, OO-style SOA in the middle, and mostly functional style at the bottom layer, something of an FP-OOP-FP sandwich. I jokingly call it sandwich oriented programming.