Enterprise integration
A C4 primer for people who have to explain systems to a board
Context, containers, components, code. The C4 model is still the fastest way to stop an architecture conversation from becoming a visio crime.
Boards do not want your sequence diagram. They want to know what talks to what, what happens if it dies, and who is awake.
The C4 model — context, containers, components, code — is still the least-worst way to tell that story. We use it on every engagement that has more than two systems, which is all of them.
The four levels, without the cult
Context. Your company, the people, the external systems. One page. If this is ugly, everything downstream is a guess.
Containers. The deployable things: the app, the API, the warehouse, the iPaaS, the agent worker. This is the diagram you should be able to draw on a whiteboard in ten minutes.
Components. Inside a container that is actually complicated. Skip this for things that are a single function.
Code. Almost never for stakeholders. Sometimes for the PR that introduces a new bounded context.
Fun fact that is not a joke
Most “AI architecture” decks we are sent skip context and jump to a model vendor logo in the middle. That logo does not have an SLA with SAP. Draw the containers. Put the model in one of them. Watch the conversation get honest.
If you want a deeper cut on moving API-led estates across clouds, that is a working session, not a blog post. Bring the diagram you already have. We will mark it up.
