Imagine that you have to create a self operating database similar to Amazon RDS. Cadence is used in multiple projects that automate managing and automatic recovery of various products like MySQL, Elasticsearch and Apache Cassandra.
Such systems are usually a mixture of different use cases. They need to monitor the status of resources using polling. They have to execute orchestration API calls to administrative interfaces of a database. They have to provision new hardware or Docker instances if necessary. They need to push configuration updates and perform other actions like backups periodically.