Wrapping Up

In this chapter, we took some time to break our growing project into bite-sized pieces. We used umbrellas, an Elixir construct that allows us to develop and test projects in isolation but integrate them into a whole. Along the way:

• We used Observer to understand the importance behind applications.
• We extracted rumbl and rumbl_web into their own child umbrella project.
• We learned to identify configuration changes, including dependencies, supervision trees, and application configuration.

Next, we’ll see how to build an independent, self-healing piece of infrastructure with OTP. When we’re done, you’ll be able to develop and test the pieces in isolation.