After that, step by step, the architecture will be evolved as follows:

Layered Architecture

Service-Oriented Architecture (SOA)

Microservices

and lastly Event-Driven Microservices Architectures  

Event-driven microservices architecture means communicating with microservices via event messages. And we saw that with Publish/Subscribe pattern and Kafka as a message broker system at microservices async communication sections.

We said we could do asynchronous behavior and loosely coupled structures with event-driven architectures. For example, services consume data via events instead of sending requests when data is needed. This capability will provide performance increases.

Event Hub

But also, there are many innovations in the Event-Driven Microservices Architectures like using real-time messaging platforms, stream-processing, event hubs, real-time processing, batch processing, data intelligence, and so on.

So, we can make this event-driven approach more generic and real-time event processing features by evolving this architecture.

According to this new event-driven microservices architecture, we can have everything connected via Event-Hubs. We can think of Event-Hubs as a large event store database that can provide real-time processing. 

https://medium.com/design-microservices-architecture-with-patterns/monolithic-to-microservices-architecture-with-patterns-best-practices-a768272797b2