Lewis DiFelice compares and contrasts Cassandra with DynamoDB:
In this post, we’ll look at some of the key differences between Apache Cassandra (hereafter just Cassandra) and DynamoDB.
Both are distributed databases and have similar architecture, and both offer incredible scalability, reliability, and resilience. However, there are also differences, and understanding the differences and cost benefits can help you determine the right solution for your application.
There’s some good info in this comparison.