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Bytesize architecture sessions - Why start with C4 Diagrams

26 Dec 2022

In my previous post about Bytesize Architecture sessions I described briefly that one of the key aspects of the session is to have time “Alone together” where each of the participants of the session will have a few minutes where they are in the same room working on the same task, but not collaborating. What I did not mention was what to do. This post fixes that.

When I started running sessions I noticed that if you ask people to draw the system without any constraints each person draws at different levels of abstraction, some will add a lot of low level details, some will do a bit of high level and a bit of low level… most won’t be able to finish which is not ideal.

I suggest drawing what is known as a Context Diagram of the system as is right now. A Context diagram is the top level of the C4 model. C4 is a modeling technique for describing your system at different abstraction levels.

If you are wondering why drawing the system as it is right now, these are a few reasons

If your team is not familiar with C4, teach them about it before a Bytesized Session. I find that most teams get there fairly fast with very little coaching.

Example of a Context Diagram. Source:

Example of a Context Diagram. Source:

If your system is too big and you think it won’t be possible to draw the whole Context diagram in one session, then break it up. Once you have a Context Diagram, it is a good idea to continue with the other parts of C4, at least do Container and Components.

If you want to discuss this post, the best place right now for me is mastodon, please message me with your comment/question.