In this book, we have seen the advantages of composing applications out of well defined components. This assembly process involves the installation of many support systems, from the operating system your application will run on, to the version of Node you will support, to the various npm modules, testing frameworks, profiling tools, and other subsystems that power an application. It is likely that you have been doing all this on a single machine—manually starting and stopping servers, updating configurations, and altering application code. Are you adding a new module? Stop the server, add the module, and restart the server.

In a production environment, this sort of ad hoc development is almost impossible, and it remains tedious regardless. How can this process be automated and streamlined so that altering the number of servers being balanced or incrementally pushing out new deployments can be done with minimum work, thus making life simpler for the folks...