Sequence / fan-out flow
Show order and branching of a request so people stop arguing from a box diagram.
Related: Reference architecture
When to use
Use when order or fan-out is the point. Do not use for static topology (reference architecture). Do not use for human swimlanes.
Guidelines
Number the hops. Fan-out is visible as multiple numbered peers, not as spaghetti.
Example
Ship confirm path
One confirm fans out to ledger, carrier, and customer notice — in that order.
Ship confirm
1 Ledger write
2 Carrier event
3 Customer notice
Numbers are order, not preference
Confirm fans to three numbered hops. Steal the numbers-as-order rule.
Rules
- Hops are numbered in execution order.
- Fan-out children share a parent hop; do not hide that.
- Title states the path’s rule (order, sync vs async) in a sentence.
- No unlabeled arrows.
User recipe
Goal: explain a request path.
Inputs: hops in order, fan-out children.
Constraints: Sequence / fan-out Rules.
Prompt skeleton: “Make a sequence/fan-out slide in family cloud-architecture using the Sequence / fan-out flow rules. Hops: [ordered list]. Fan-out: [children].”
Anti-patterns
- A topology diagram with a few extra arrows.
- Colors instead of numbers for order.