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; arrows are connectors
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
Pick family: Cloud architecture first.
Insert objects:
- Text: title stating the path’s rule, kicker, source line
- Panel (optional): for grouping if needed
- Junction: for each hop where requests branch or merge
- Connector: numbered arrows between junctions
Assemble:
- Number connectors in execution order
- Show fan-out as multiple connectors from one junction to multiple children
- No unlabeled connectors
Anti-patterns
- A topology diagram with a few extra arrows.
- Colors instead of numbers for order.