The microkernel architecture
The microkernel architecture shown in Figure 4-7 defines a core system with an API that allows plug-in enhancements. Two architectural quantum sizes exist for this architecture: one for the core system and another for the plug-ins. Architects typically design the core system as a monolith, creating hooks for well-known extension points for plug-ins. Plug-ins are usually designed to be self-contained and independently deployable. Thus, this architecture supports positive, incremental change, and developers can design for testability and facilitate fitness function definition. From a technical coupling standpoint, architects tend to design these systems with low coupling for practical reasons, which is related to keeping the plug-ins independent from one another to simplify them.
Link:: Building Evolutionary Architectures
Один из подходов к построению архитектуры сервиса.