Building the application

Now that we have understood not just the methodology of designing a layered Fabric application but also the philosophy behind it, we can dive into the implementation. In the previous two chapters, we discussed how to implement and test the lowest layer, or the chaincode. Therfore, we can assume that the reader is now ready to add the middleware and application layers, which is what we will demonstrate in the following sections.

A prerequisite for the testing of middleware and application code is a running network. Before proceeding to the next section, please ensure that the sample four-organization network we configured and launched in the Setting up the development environment section in Chapter 3, Setting the stage with a business scenario, is still up and running.