In this chapter, we touched on data modeling done in a different era. We discussed some of the common problems in traditional data modeling if you were working in a microservices environment. You were introduced to a pattern for long-running transactions, which was the Saga pattern. Also, we looked at DDD. Further, we saw how to model a sample application in a microservice environment. In the next chapter, we will explain how to do testing in microservice-based architecture.