I’ve known for some time that Nikon actually designs their own sensors, to a fairly minute level of detail. I think this is almost unknown in the photo community; most people just assume that “design” in Nikon’s case simply consists of ordering-up different combinations of specs from sensor manufacturers, picking a feature from column “A”, another from column “B” and so on, like a Chinese restaurant menu. In actuality, they have a full staff of sensor engineers who design cutting-edge sensors like those in the D5 and D850 from the ground up, optimizing their designs to work optimally with NIKKOR lenses and Nikon's EXPEED image-processor architecture.

Nikon really needed this PR article. Especially as 100% of all mass cameras have Sony sensors now.

Yes, in the past at this place they designed sensors and still do something now, but not for any mass camera (D5 is not mass camera, for D850 mentioned in article I have huge doubts). So, mostly they can only do slight changes to Sony design.

https://www.imaging-resource.com/news/2018/07/17/pixels-for-geeks-a-peek-inside-nikons-super-secret-sensor-design-lab