We're in the process of improving the suggested articles/discussion around the site and I'm looking at implementation options.
The most appealing option I've found is Recombee, which seems well-designed and well-documented. We'll design this system so that we can swap this out for something else in the future, so I'm not itching to go after a lower-level API or library for the time-being. Recombee seems like a goldilox solution in terms of not being too low-level or high-level and the docs make sense.
But I'd love input if anyone has any thoughts on the matter.