If the position requires a Confidential clearance, you might not be out of luck - these go through quickly. Sometimes, a contractor can spend a "silver bullet" to expedite a Secret of TS clearance for a key person.
If you want the job, don't let the clearance stop you - you maight be able to get hired and put to work without the clearance up front.
As pointed out above, DIS investigations are backed up in the extreme, and, the contractor may just be trying to get by on the cheap. If they want to hire you, the clearance won't be much of a barrier.
If you are pursuing an engineering job at Boeing, go ahead and apply - we are hurting for help in several disciplines, and they post this requirement on nearly every job posting whether it is true or not. What often happens at this company is that an uncleared person will start work and free up a cleared person to fill a position.