The architecture of otto.de is based on the concept of vertical decomposition: the whole system is vertically split into several loosely coupled applications.
Every „vertical“ is responsible for a single business domain such as „Order“, „Search & Navigation“, „Product“, etc. It has its own presentation layer, persistence layer and a separate database. From the development perspective, every vertical is implemented by exactly one team and no code is shared between the different systems.
For some time, a different approach to decompose large systems is becoming more and more popular: microservices. What are the similarities and differences of both kinds of architectures and how is it possible to get the best of both? This is what I want to discuss in this text.