C4 Models as Code

YOW! London 2022

"Diagrams as code", as featured on the ThoughtWorks Tech Radar, is becoming a popular way to create software architecture diagrams for inclusion in long-lived documentation. The benefits of creating diagrams from text are well understood - text is version controllable, easy to diff, easy to integrate into build pipelines, and automatic layout facilities allow authors to focus on content. The majority of these tools (e.g. PlantUML and Mermaid) are focussed on diagramming though, and require you to create one text file per diagram, with only a limited ability to reuse diagram elements across multiple diagrams. At scale, this causes maintenance problems, and leads to inconsistencies between diagrams.

This talk will introduce and demonstrate the open source Structurizr DSL - a way to create a model of your software architecture using a textual DSL that's specifically targeted towards the C4 model. We'll also see how the DSL separates content from presentation, allowing you to render your diagrams with a number of tools, which in turn offers some answers for the tricky question of how to use the C4 model at scale.