Steve Hoffman, Daniel GB In this presentation, we will talk about Uber's journey from using Cassandra as one of the primary databases to an in-house scalable and consistent replacement built on top of MySQL. We will talk about some of the challenges related to reliability, developer productivity and efficiency that we faced when using Cassandra. We will go over the architecture of the in-house replacement, the design principles that we followed and talk about the different tradeoffs we made. Finally, we will talk about the migration journey and how we were able to achieve drop-in-place replacement for thousands of micro-services.