Detecting Process Starts and Process End from DelegateExecution object

See below post

getBpmnModelElementInstance()
Returns the currently executed Element in the BPMN Model. This method returns a FlowElement which may be casted to the concrete type of the Bpmn Model Element currently executed.

If called from a Service ExecutionListener, the method will return the corresponding FlowNode for ExecutionListener.EVENTNAME_START and ExecutionListener.EVENTNAME_END and the corresponding SequenceFlow for ExecutionListener.EVENTNAME_TAKE.

https://docs.camunda.org/javadoc/camunda-bpm-platform/7.6/?org/camunda/bpm/engine/delegate/DelegateExecution.html