The software layer between the operator and the viewer. RDK, Android TV Operator Tier, AOSP and Linux middleware. Launchers, guides, playback, CAS and DRM, OTA and device management — on fleets measured in millions of boxes, where the hardware cannot be swapped and a regression is a call-centre spike. Capability groups: Platforms & operating systems, Operator experience, Playback & security, Operator systems, Device & input.