The well-factored approach to securing ROI on your service investment: part three
The right service boundaries hide complexity – domain and technical.
When designing services, it’s important to have the high cohesion of related concepts — things that change at the same time. Low (loose) coupling is about pulling unrelated concepts apart — things that can be built, tested, deployed, evolved and scaled independently. In a tightly coupled (tangled) system, introducing a simple change causes a ripple effect across the entire system; that can be very expensive.