Xandr/Microsoft also lists Nuviad as a "partner which may receive Platform Data":
https://docs.xandr.com/bundle/service-policies/page/third-party-providers.html
Here's Nuviad boasting about '2.5 billion user profiles' and 'analyzing over 700k ad opportunities every second'. From an Amazon AWS event in 2018:
https://de.slideshare.net/AmazonWebServices/success-has-many-query-engines-tel-aviv-summit-2018