Cassandra - the database you can’t turn off
Cassandra is the second most popular NoSQL storage in the world after MongoDB and, for a good reason, is trusted by Netflix, Apple, FaceBook, Digg, Twitter and other great companies. However, learning curse is very steep - you need to invest vast amount of time to switch your mindset, grasp its concepts and nuances.
Because journey is long, you need some inspiration. Here is one - an introductory video by Datastax engineer Christopher Batey.
By the way, Datastax has just released new course - Cassandra Data Modeling. I plan to attend course soon, so you can give it a try too.