Mermaid is a text-based diagramming tool for people who would rather write diagrams than drag boxes around a canvas. It uses a Markdown-like syntax to describe flowcharts, sequence diagrams, class diagrams, state machines, timelines, Gantt charts, entity relationship diagrams, and more. For a technical blog, Mermaid is a very good default. The diagrams live next to the article, they can be reviewed in Git, and they are easy to update when the system changes. Static image diagrams look nice un...