A strange question for background check

[Dogdogdog]

We need to pass three background screen, security clearance, criminal clearance, and other clearance, right?
Since the security clearance need at least one months, why some people got their test invitation after several days of IP ? and got DM after several days of test?

 

[SpiceIsland]

Yes you're right we need an answer here!

Some offices do test interviews before background checks are complete.