"Mermaid: a Javascript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams."
This was one of the best things I learned at my first job. The capability of finding an error-proof solution is so satisfying.
One of the best examples I know is:
- The Heart Valves, are an error-proofing example in nature that prevent the back-flow of blood