6 months ago we finished migrating the Workjam channels module datastore. Reasons for the switch was frustrations with AWS read/write capacities being frequently exceeded because of unplanned explosive growth, hard limitations on batch updates and interesting Cassandra features such as consistency tuning and Datastax's Solr integration. The decision to use Cassandra might not have been the most practical one as our needs would probably have been better served by a document store such as MongoDB, as we are not dealing with intense document update operations, but Cassandra was used throughout the company and the aim of stack uniformity was favoured over functional needs. We implemented the migration with the aim of incurring no downtime and the ability to rollback by sending write commands over AMQP. Overall the migration went smoothly, the devs learned all the powers of Cassandra and got acquainted with its many constraints. Datastax's Solr integration made the search implementation very simple but we were very disappointed in some of Datastax's Solr integration limitations (ex: search highlights being deprecated).