Real-time, machine-learning-driven personalization in Marketo emails - 3rd party tools?

Hello community! First-time poster here! 😁 

Wondering if anyone out there is successfully using real-time, machine-learning-driven personalization capabilities within their Marketo email/engagement programs? I would love to learn more about how you're implementing this, and the tools/platforms you're using.

I am familiar with Marketo's ContentAI feature (if you're using this, would still love to hear more), but am also interested in exploring 3rd party solutions that can be integrated with my organization's Marketo instance.

Thanks in advance. Anything helps!