Yes, I have implemented a few content-based recommendation engines (referring to Chudi's taxonomy). The biggest existential threat is dealing with colleagues th

Yes, I have implemented a few content-based recommendation engines (referring to Chudi's taxonomy). The biggest existential threat is dealing with colleagues that want to question your work for not using f^xyz method that they have heard about. Having a straightforward evaluation framework in place to evaluate your results will go a long way towards ensuring the adoption and longevity of what you create. I grow my own analysis code but use search APIs for storage and access (Lucene or Algolia)