In one scene, Robert De Niro's character is confused as to who Jay-Z is. This is an in-joke about the beef Robert De Niro and Jay-Z had between 2012 and 2016.
When Ben tells Jules that he knows a faster way to get to the office, he mentions that he used to drive a cab. DeNiro's breakout character Travis Bickle was a cab driver.
Ben's old company Dex One was a real print company which actually survived into the digital media age, but in 2016 was absorbed by another company.
Writer and director Nancy Meyers approached Jack Nicholson for the role of Ben Whittaker. Nicholson is mentioned in Jules' philosophic rambling at the bar.