Reading about ringpop, came across this statement

> Ringpop, a library for building cooperative distributed systems, solved some of Marketplace’s problems before its adoption in other teams at Uber and beyond. It gives the high-availability, partition-tolerant properties of distributed databases like DynamoDB or Riak to developers at the application level.

I am wondering about the need to have your app services communicate with each other (is that because these are stateful applications ?) or have I missed the point completely ?