I have been working on AI/recommendations(for music) for a while now and run a few experiments with some ALS models which have shown promising results during A/B tests. Would like to build a proper recommendation system with online and offline models. I have searched around and elastic search and Solr come up as good ways of building one (reduce the recommendation problem to an implicit search problem) but after talking to a few folks at work it seems like it may not be the most scalable or simplest solution for us. What are some other architectures to consider? Are there any good resources for this? After a lot of searching, I have not been able to find much other than the aforementioned Solr/elasticsearch solutions.
Here are a few links I found online while researching this.
https://www.elastic.co/blog/looking-at-content-recommendation-through-a-search-lens
https://mapr.com/blog/inside-look-at-components-of-recommendation-engine/#.VSv8o_nF81J