Just as there is no formal definition of the term microservices, there’s no standard model that you’ll see represented in every system based on this architectural style. But you can expect most microservice systems to share a few notable characteristics.

First, software built as microservices can, by definition, be broken down into multiple component services. Why? So that each of these services can be deployed, tweaked, and then redeployed independently without compromising the integrity of an application. As a result, you might only need to change one or more distinct services instead of having to redeploy entire applications. But this approach does have its downsides, including expensive remote calls (instead of in-process calls), coarser-grained remote APIs, and increased complexity when redistributing responsibilities between components.

Second, the microservices style is usually organized around business capabilities and priorities. Unlike a traditional monolithic development approach—where different teams each have a specific focus on, say, UIs, databases, technology layers, or server-side logic—microservice architecture utilizes cross-functional teams. The responsibilities of each team are to make specific products based on one or more individual services communicating via message bus. That means that when changes are required, there won’t necessarily be any reason for the project, as a whole, to take more time or for developers to have to wait for budgetary approval before individual services can be improved. Most development methods focus on projects: a piece of code that has to offer some predefined business value, must be handed over to the client, and is then periodically maintained by a team. But in microservices, a team owns the product for its lifetime, as in Amazon’s oft-quoted maxim “You build it, you run it.”