Monolith Modularization Towards Microservices: Refactoring and Performance Trade-offs

The agility inherent to today’s business promotes the definition of software architectures where the business entities are decoupled into modules and/or services. However, there are advantages in having a rich domain model, where domain entities are tightly connected, because it fosters reuse. On the other hand, the split of the business logic into modules and its encapsulation through well-defined interfaces introduces a cost in terms of performance. In this paper we analyze the impact of migrating a rich domain object into a modular architecture, both in terms of the development cost associated with the refactoring, and the performance cost associated with the execution. Current state of the art analyses the migration of monolith systems to a microservices architecture, but we observed that migration effort and performance issues are already relevant in the migration to a modular monolith.