Ask HN: Content Personalization in the Back-End

I've been looking and working with some content personalization tools (Squeezely, Google Optimize) for some time now. Although they work okay and seem to deliver a good ROI, I was thinking how this is going to work when people start browsing anonymously more and more.

This means most tracking pixels, snippets will cease to work properly and aggregating users will be a tricky task.

I was wondering if anyone knows any Content personalization tools that work on a back-end level. And thus are more future proof.