TL;DR: we switched from RethinkDB and ElasticSearch to Postgres, leaning heavily on Haskell in order to fill in some of the gaps quickly. The project was a success, and we’re very happy with the switch. Haskell has been invaluable for refactoring safely and confidently. MotivationAt Lumi, our backend stack has historically used RethinkDB for the primary database and ElasticSearch for indexing and