Use Auto Layout for Architecture Diagrams

What you'll build

In this tutorial, you will take a cluttered, disorganized graph of services and databases, and use Rekhic's Dagre layout engine to automatically format it into a clean, hierarchical architecture diagram.

Before you start

• Open any diagram on the canvas, or create a quick set of 5-8 connected nodes in random positions to see the auto layout transformation in action.

Step 1: Examine the Raw Graph

1. Place or import several nodes on the canvas.
2. Connect them with directional connectors (e.g. Client -> Gateway -> Service A, Service B -> Database).
3. Notice if edges cross over each other awkwardly or if node spacing is uneven.

Step 2: Trigger Top-to-Bottom Auto Layout

1. Click the Auto Layout button in the canvas toolbar.
2. Observe how the layout engine:
   • Identifies root ingress nodes (nodes with only outgoing edges) and places them on Tier 1.
   • Positions intermediate routing services on Tier 2.
   • Arranges downstream persistence stores on Tier 3.
   • Adjusts horizontal spacing between sibling services to prevent edge overlap.

Step 3: Experiment with Left-to-Right Layout

1. For data pipelines, ETL workflows, or sequential event streaming architectures, a horizontal flow is often preferred.
2. Change the layout direction setting from TB (Top-to-Bottom) to LR (Left-to-Right).
3. The layout automatically realigns with sources on the far left, transforms in the middle, and sinks on the right.

Review the generated architecture

• Check that the logical flow of data follows the direction of the connectors.
• Verify that edge bends are clean 90-degree right angles.
• If the layout looks great, proceed to custom styling. If you prefer your original layout, simply press Cmd/Ctrl + Z to undo.

Customize the diagram

1. Now that the primary tiers are arranged, you can fine-tune individual nodes:
   • Nudge a database node slightly to accommodate a larger bounding box.
   • Add a container around the services on Tier 2.
2. Adding a group container does not break auto layout; you can run auto layout again whenever you add new nodes.

Export your result

1. Click Export to download a polished PNG image for your architecture review meeting.
2. Click Export Markdown to generate the updated relationship tables.

Tips

• Disconnected nodes (nodes with no edges) are neatly aligned in a separate utility row by the layout engine.
• If your diagram contains cyclical dependencies (e.g. Service A calls Service B which calls Service A), Dagre gracefully handles the cycle by creating a feedback loop edge.

Limitations

• Auto layout calculates coordinates algorithmically based on topological sort and edge weight. It does not have semantic knowledge of physical data center geography. Use manual grouping for physical network topologies.