Microservice architecture has been prevalent for the last decade. This type of architecture is a proven solution to scalability, team autonomy, and complexity challenges. The industry acknowledges that this approach effectively addresses these issues. Through a literature review where we mainly examine the case for microservice architecture, along with a case study, we interview the project architect involved in migrating a system away from microservice architecture. Understanding the difficulties that people face when dealing with microservices is crucial. We need to identify the situations where it is appropriate to question their usage.

Through our study, we also examine the process of raising the granularity in a system, i.e. migrating it towards a microservice architecture, as well as what might be the unique difficulties in moving in the opposite direction. The study does not cover differences in technically oriented quality attributes between architectural designs but how teams, architects and developers work with them.

The results show that several factors, such as team size, number of teams and the scope of the system, play into whether microservices are suitable for a particular system or not, or what alternatives might suit it better. The results provide valuable insights into things worth considering when making architectural decisions.