What company did the designer work for the company which then owned Donkey Kong?

The designer who created Donkey Kong is Shigeru Miyamoto, and he worked for Nintendo. At the time of Donkey Kong's release in 1981, Nintendo was primarily known for its arcade games and had recently transitioned from being a playing card company to a video game developer. Miyamoto's innovative work on Donkey Kong helped establish Nintendo as a major player in the gaming industry.