6.1Start with the mental model

A trivial flow is linear:

HTTP Listener
   ↓
Transform
   ↓
Salesforce Upsert
   ↓
Response

A realistic flow branches:

HTTP Listener
   ↓
Validate
   ↓
Choice
 ┌───────────────┐
 │               │
new customer   existing customer
 │               │
Create          Update
 └───────┬───────┘
         ↓
      Response

Or loops:

Customers[]
    ↓
For Each
    ↓
process customer

Or performs independent operations:

              ┌→ Salesforce
Input → Split ┼→ Database
              └→ Logging API

That is orchestration.