A close up of one of the typewriters in the opening shows that the Office Of Interchange is using at least one IBM Selectric typewriter with the typical "golf ball" type head. Inside the Office Of Interchange there is a mix of vintage office technology. Typewriters share desk space with early IBM-like desktop computers and dot matrix printers. The OI uses dated technology to try and "stay in line" with how advanced the alternate universe's technology is; as they have advances in medicine, but not so much in computers & personal electronics.
The former Berlin Tempelhof Airport was used as location for The Office Of Interchange.
This includes the subterranean street which is used to enter or leave the Office Of Interchange by car.
At one point J.K. Simmons refers to a portal connecting the two dimensions. In Portal 2 (2011), Simmons voiced the inventor of the game's Portal technology.