Best Software Architecture Visualization Tools for Engineers
You need to explain an appointment booking system. A customer uses the booking service, the service sends a confirmation through an email provider, and someone reviewing the diagram needs to know where your system ends, because the email provider belongs to somebody else.
I'd start with that boundary. For a README, Mermaid is my first choice. If several diagrams need to describe the same system, I'd look at Structurizr before maintaining each view separately.
Pick the workflow before the tool
| Tool | Where I'd start with it | What I'd check before committing |
|---|---|---|
| Mermaid | A small diagram in documentation | Does the place publishing your docs render it? |
| Structurizr | Several C4 views from one model | Who will maintain the model? |
| PlantUML with C4-PlantUML | C4 diagrams alongside other UML diagrams | Can the team maintain the text definitions? |
| Graphviz | Rendering relationships supplied by a script | Where do the nodes and edges come from? |
| Lucidchart | Discussing a diagram with people who want a canvas | How will feedback become an approved update? |
| Microsoft Visio | A team already using Visio for documentation | Does the available edition include the shapes you need? |
| Sparx Enterprise Architect | Maintaining implementation links in a formal model | Who owns those links as implementation changes? |