Creating Software with Modern Diagramming Techniques

Create Clear Boundaries with Subgraphs

To handle the expected demand at Streamy, they want to leverage a Redis cache to prevent repeated calls to downstream APIs.

We now want to add that final Redis container and add the interaction between the mobile application and the web application.

I find it useful to display the boundary of the system on the container diagram, in case the colors aren’t clear enough. For that, we can leverage what’s called a subgraph in a flowchart. Anything within that boundary belongs to the system we’re architecting. I think of it like the lens for this diagram, where we’ve zoomed in one one of the boxes from the system context diagram. We can add the boundary, using a subgraph, like so:

flowchart TD
 User["Premium ...