You are right this is currently not possible. For updates of existing applications there is no down time (just upgrade the docker images). When you add a new application, though, there is the downtime needed for shutting down and starting up (< 30 sec on our setups). We do plan to look into hot reloading of the application. I don't see specific issues for adding applications a priori, but whether hot reloading for all configuration settings will be possible remains to be seen.