You might be wondering about one thing as you consider this system to design dissonant services that work in congress: what's the communication platform? To answer this, we'll say there is an easy answer and a more intricate one.

The easy answer is REST. This is great news, as you're likely to be well versed in REST or you at least understand some portion of it from Chapter 5, Frontend Integration with RESTful APIs. There we described the basics of API communication utilizing RESTful, stateless protocols and implementing HTTP verbs as actions.

Which leads us to the more complex answer: not everything in a large or involved application can operate on REST alone. Some things require state or at least some level of long-lasting consistency.

For the latter problem, most microservice architectures are centered on a message queue as a platform for information sharing and dissemination. A message queue serves as a conduit to receive REST requests from one service and holds it until another service retrieves the request for further processing.