sequence2.plantuml

@startuml
scale max 1000 width
actor "Admin"
actor "Timer"

group Synchronous Process
  "Admin" -> "Web UI" : postProcessRequest()
  "Web UI" -> "API": storeProcessRequest()
  "API" -> "DB": insert()
end

group Asynchronous Process
  "Timer" -> "API": batchProcess()
  "API" -> "API": listPendingRequests()
  "API" -> "DB": select()

  loop Item Processing
    "API" -> "API": process()
  end
end

@enduml