Diagrams are essential for explaining complex systems and processes in technical documentation. Mermaid makes it easy to create and maintain diagrams using a simple markdown-like syntax, directly in your content files.

In this post, I’ll show several examples of diagrams you can create using Mermaid.

Flowchart Example

Let’s start with a basic flowchart showing a deployment process:

Deployment flow: code review, build and test, staging, production, monitoringDeployment flow: code review, build and test, staging, production, monitoring

The code to create this flowchart is surprisingly simple:

flowchart TD
    A[Code Changes] --> B{Code Review}
    B -->|Approved| C[Build & Test]
    B -->|Rejected| A
    C --> D{Tests Pass?}
    D -->|Yes| E[Deploy to Staging]
    D -->|No| A
    E --> F{Staging Validation}
    F -->|Pass| G[Deploy to Production]
    F -->|Fail| A
    G --> H[Monitor]

Sequence Diagram Example

Sequence diagrams are perfect for showing interactions between components:

Read-through cache: the API checks the cache and falls back to the databaseRead-through cache: the API checks the cache and falls back to the database

Class Diagram Example

Class diagrams help visualize the structure of a system:

Class diagram: an Application runs on a Server and uses DatabasesClass diagram: an Application runs on a Server and uses Databases

Gantt Chart Example

Gantt charts are useful for project planning:

Gantt chart of a DevOps project timeline from planning to monitoringGantt chart of a DevOps project timeline from planning to monitoring

Tips for Using Mermaid

  1. Keep it simple: Focus on clarity rather than creating overly complex diagrams
  2. Use consistent styling: Follow the same conventions across all your diagrams
  3. Add meaningful labels: Make sure relationships and actions are clearly labeled
  4. Test your diagrams: Some complex syntax might not render correctly in all cases

Conclusion

Mermaid diagrams are a powerful way to enhance your technical documentation with visual representations that are:

  • Version controlled with your content
  • Easy to update and maintain

By integrating diagrams directly in your markdown content, you can create more comprehensive and understandable documentation for your projects.