@startuml
participant Controller
participant Service

Controller -> Service: call(params)
note right
  **Step 1**
  Service is called with given params
end note

Service -> Service: ...
note right
  **Step 2**
  Service interacts with other objects (eg. ActiveRecord models)
  to perform a certain use case
end note

Controller <-- Service: success/failure
note right
  **Step 3**
  Service gives control
  back to the controller
end note
@enduml

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