light-4j is aiming microservices and design of microservices is more art other than technique. When you break a business application to smaller pieces, there is a threshold. If it too fine-grained, then the performance will suffer, but if it is too coarse-grained, then the benefit of microservices will be diminishing.
The big portion of design work for microservices is to functionally divide an application to multiple services and define the communication contract between these services with OpenAPI specifications.
Here is a list of design decisions for microservices:
Work-in-progress: * How to design microservices for brand new project/product