Architecture Types

Strangler

Effectively two applications living in their own domain spaces. The new service slowly "strangles" the old one. The client has to be updated to use the new service.

Saga

Needed when there are many services with their own respective database, and transactions require a long time.

Two ways:

Orchestrated

Centralised. A central service keeps track and asks others to roll back in case of an error.

Choreographed

Each service raises events and listens. In case of an error all roll back.

Aggregator

A central service aggregates responses from multiple services. Send this aggregate response to the client.