We deal with complicated and complex applications on a daily basis, codebases that are filled with classes that do too many things. One design pattern that can help us with this is CQRS, Command Query Responsibility Seggregation. The idea behind CQRS is to split our models in two - the Command for writing, and the Query for reading. Applying CQRS can lead us to a more maintainable code, code that follows the SOLID principles more closely.
At the heart of CQRS lies the Service Bus - a transport mechanism responsible for dispatching our command, event, and query messages to their destinations.
This talk will give an overview of the CQRS pattern and take a closer look at the different types of service buses - command, event, and query ones. Main takeaway will be practical information on why, when, and how to use them, with emphasis on their differences. We'll also take a look at some of the PHP libraries out there that help us work with service buses like Prooph Service Bus, Simple Bus, Tactician, to name a few.