Slides: https://www.slideshare.net/DataStax/what-we-learned-about-cassandra-while-building-go90-christopher-webster-thomas-ng-aol-c-summit-2016 | go90 is a mobile entertainment platform offering access to live and on demand videos. We built the web services platform and social features like activity feed for go90 by making heavy use of Cassandra and Scala, and would like to share what we learned during development and while operating go90. In this presentation, we cover our data model evolution from the initial prototypes to the current production version and the significant performance gain by using a better data model. We will explain how we apply time series data modeling and the benefits of using expiring columns with DateTieredCompactionStrategy. We will also talk about interesting experiences related to table modifications, tombstones and table pagination. On the operations side, we will discuss our findings on java driver usage, performance, monitoring, cluster maintenance, version upgrade, 2-way ssl and many more. We hope you can learn from our mistakes instead of making them yourself! About the Speakers Christopher Webster Software Engineer, AOL Christopher Webster works on the web services platform for the go90 AOL project. Previously he was a Computer Scientist for the Mission Control Technologies project at NASA Ames Center. Chris worked as a senior staff engineer at Sun Microsystems for Project zembly, the cloud development and deployment environment as well as technical lead in many NetBeans projects. Chris is an author of the NetBeans Field Guide and Assemble the Social Web With Zembly. Thomas Ng Software Engineer, AOL Thomas Ng is a software engineer at AOL, building web services for the go90 mobile entertainment platform using Cassandra, Scala and Kafka.