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Derek Comartin

Commands & Events: What’s the difference?

One of the building blocks of messaging is, you guessed it, messages! But there are different kinds of messages: Commands and Events. So what’s the difference? Well, they have very distinct purposes, usage, naming, ownership, and more! YouTube Check out my YouTube channel where I post all kinds of content that accompanies my posts including this video showing everything in this post. Commands The purpose of commands is the intent to invoke behavior. When you want something to happen within your system, you send a command. There is some type of capability your service provides and you need a way to expose… Read More »Commands & Events: What’s the difference?

Microservices gets it WRONG defining Service Boundaries

Logical boundaries aren’t physical boundaries. A service boundary can be a one-to-one mapping of logical boundary and physical boundary but they don’t have to be. A logical boundary can have many physical boundaries and a physical boundary can be composed of many components from many logical boundaries. Do we have microservices to thank for the idea that the physical, development, and logical views are the same? This introduces a pile of unneeded complexity related to deployment, versioning, and data duplication. YouTube Check out my YouTube channel where I post all kinds of content that accompanies my posts including this video showing everything… Read More »Microservices gets it WRONG defining Service Boundaries

Real-World Event Driven Architecture! 4 Practical Examples

Event Driven Architecture has many benefits. Loose and temporal coupling, scaling, resilience, and more. But what does that mean? What are some actual use-cases? I’m going to describe 4 practical examples of real-world event driven architecture. YouTube Check out my YouTube channel where I post all kinds of content that accompanies my posts including this video showing everything that is in this post. External Integrations The first practical use-case for real-world event driven architecture is integrating with external 3rd party services. In a lot of systems, when something occurs (an event) you need to interact and exchange data with a 3rd party… Read More »Real-World Event Driven Architecture! 4 Practical Examples