
Monolithic migration using SOA
The following diagram shows a monolithic application, broken down into three micro applications:

The last possibility is transforming a monolithic application into smaller units after hitting the breaking point with the monolithic system. They would have broken the application into smaller, physically deployable subsystems, similar to the Y-axis scaling approach explained earlier, and deployed them as web archives on web servers, or as jars deployed on some homegrown containers. These subsystems as service would have used web services or other lightweight protocols to exchange data between services. They would have also used SOA and service-design principles to achieve this. For such organizations, they may tend to think that microservices are the same old wine in a new bottle.