UPDATE: This article refers to our hosted Elasticsearch offering by an older name, Found. Please note that Found is now known as Elastic Cloud. The previous article in this series, Elasticsearch from the Bottom Up, covered essential data structures within a single shard.
At the end of the day, Command and Query Responsibility Segregation (CQRS) is software design that separates the code that alters state and the code that just reads state. That separation can be logical and based on different layers. It can also be physical and involve distinct tiers.
MassTransit is a free, open source, lightweight message bus for creating distributed applications using the .NET framework.
Andrea Saltarello shows how to evolve systems architecture leveraging CQRS principles and NServiceBus Sagas. When speaking about CQRS, most developers focus on topics such as scalability, ad hoc read models, and event sourcing.