If you are looking for the Netflix application file (APK) to install on a device that doesn't have the official Google Play Store (like certain projectors or older Android TVs):

"OPK" might be a typo for (Open Connect Appliance), which is the heart of Netflix's content delivery network (CDN).

: The software running these appliances is built on open-source tools like FreeBSD , Nginx , and BIRD . You can find more technical details in the official Netflix Open Connect Deployment Guide . 3. Netflix Open Source Software (OSS)

: These servers store copies of Netflix content locally within the ISP's network. When you hit "play," the video streams from a server very close to you rather than from a distant data centre.

Netflix is famous for sharing its internal technology with the developer community: