Which company produced Stranger Things alongside Monkey Massacre Productions?

21 Laps Entertainment produced Stranger Things alongside Monkey Massacre Productions.

21 Laps Entertainment is an American film and television production company founded and run by filmmaker Shawn Levy. The company’s trade name is 21 Laps, Inc., and it became closely associated with Stranger Things from the series’ development through its early seasons. Monkey Massacre Productions is the production company connected to the Duffer Brothers.

The partnership began before the show reached Netflix. In early 2015, Dan Cohen, then a vice president at 21 Laps, brought the Duffer Brothers’ script to Shawn Levy. Levy and Cohen invited the brothers to their office, acquired the rights, and helped move the project toward Netflix. That development history explains why 21 Laps is listed among the show’s production companies rather than merely as a later distributor.

The company was originally founded as Wunjo, Inc. in 1999 and adopted the 21 Laps Entertainment name in 2005. Its name came from the number of laps Levy’s eldest daughter ran in a jogathon at age five. Other 21 Laps projects include Real Steel, Arrival, Free Guy, and The Adam Project.