You often hear about the top-notch employee perks at Facebook: Its headquarters in Menlo Park offers free meals, dry cleaning and even a barber shop.

What you don't often hear about are the contract workers, from bicycle mechanics to cafeteria workers, who keep everything running.

Full-time employees "have free laundry, haircuts, free food at any time, free gym," Maria Gonzalez, a janitor at Facebook, tells The Guardian. "It's not the same for janitors. We just leave with the check."

And despite Facebook's minimum wage of $15, which it established for all of its contractors in 2015, the paychecks don't go far around San Francisco, where the cost of living is 62 percent higher than the U.S. average.

One contractor, Jiovanny Martinez, can't make ends meet with just his wages from the tech giant. The security guard at Facebook also drives Lyft and works as a park ranger to support his family, The Guardian reports.