@jholkeboer depending on what is needed you have options on how to start things: https://github.com/tolitius/mount#composing-states you could use clojure.test.use-fixtures to start parts of you app that is needed for tests, a db instance in your example (here is a simple example from the internal mount tests: https://github.com/tolitius/mount/blob/master/test/core/mount/test/parts.cljc#L17-L26)