Netflix needs to promote its never-ending new original titles to the world. For them, this means creating different ads per TV show or movie, for each region or country.
It is not a surprise, that most of their engineering efforts went into creating a dynamic ads creation, quality control and optimization platform.
In the cycle of ad creation, attribution and optimization, they’ve put most of the work in the first step.
If you want to learn more on how they did it, check this blog post.