In our Clojure web app, we started out using MongoDB, and eventually we migrated to Datomic. It&#x27;s a nice compromise between relational DBs like SQL, and &quot;dynamic&quot; DBs like NoSQL. So far it&#x27;s been a huge performance win. Queries are faster here because we have relational data, and we don&#x27;t do too many writes, so the trade-off worked perfectly for us. Plus, the API is way nicer to work with than SQL-based anything.