We're a development team working on B2B healthcare applications written in Clojure. As an experiment, we put started to use the Datomic database for some small-scale production applications in early 2015. Over the course of a year, we've gathered more experience with using Datomic, learned to appreciate its features and hate its weaknesses. In the talk, I will show some usage patterns and techniques that are enabled (or enforced) by Datomic's architecture and feature set.