Once we have assured that the different microservices are able to operate seamlessly with each other to generate a meaningful result, it's time to validate if the whole system, consisting of the different microservices and their dependencies, work without any problems. This kind of testing aims to cover the request-response cycle through the whole system, validating the outputs produced in the intermediate stages, as well as the final stages. This is known as end-to-end testing.

This kind of testing ensures that the system as a whole behaves in a well-defined manner and does not produce any surprises when an input that is beyond the domain of the system is provided to the system.