Choosing the Right Diagram Type

Pick the diagram by the question

People argue about notation when they should ask what they need to explain. A component or architecture diagram answers what the parts are and how they connect. A sequence diagram answers in what order things happen between them. A data flow diagram answers where information moves and where it is stored. An entity diagram answers what the data looks like, and a deployment diagram answers where the software actually runs.

When an architecture diagram is enough

For most design discussions a single boxes and arrows picture of components is the right tool. It is quick to read, tolerant of imprecision and easy to redraw as the design changes. Keep it to one level of detail: if you find yourself drawing both a whole subsystem and a single function in the same picture, split it in two.

When to switch to a sequence diagram

As soon as order, retries or timing matter, such as an authentication handshake or a payment with a webhook, numbered arrows on an architecture diagram start to strain. The OAuth template shows a workable compromise: numbered, labelled arrows between the same few nodes. If the numbering gets past about eight steps, move to a dedicated sequence diagram. Mermaid import in ArchBoard supports sequence diagrams as editable shapes.

Deployment and data views

Show deployment when the audience cares about regions, clusters or networks, and show data when they care about copies and ownership. Resist combining them with the logical architecture on one canvas; use separate pages in the same scene so each picture stays honest and readable. Pages are the tabs at the bottom of the ArchBoard editor.

Try it with a template

• CQRS
• OAuth 2.0 Login Flow
• Kubernetes Cluster with Ingress