Job or Work Verification before Case Officer Allocation

[khokhar80]

Hi,
I am Pakistani and would like to know that how the DIAC persons verify the job, either they come physically at the current workplace, and asking questions to employer / manager about main applicant job status and experience or they directly ask questions to main applicant about the job specifically related to field.

When DIAC person verify job or current workplace? Does they come after CO assigned to the application or before? Thanks for reply.