Domain Driven Design

I often read comments about how Domain Driven Design is too complicated or overkill. Then there are others new to DDD that want to apply it, especially the technical patterns, everywhere. So the question is, should you use Domain Driven Design? The answer is somewhere in the middle. Let me explain. 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. Large System First, let me define some context on what I’m going to refer to in the rest of this post. When talking about… Read More »Should you use Domain Driven Design?

Value Objects are a great way to explicitly capture concepts within your domain. They are immutable, always in a valid state, provide behavior, and are defined by their value. This sounds a lot like Messages (Commands, Events) that are also immutable and should be in a valid state. However, exposing your Value Objects by using them within Commands or Events can have a negative impact on your ability to evolve your domain model. 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. Value Objects… Read More »Leaking Value Objects from your Domain

Always having your Domain Model in a valid state means it will be predictable. You’ll write less defensive code or conditional code because your domain objects will always be in a valid state. Using aggregates is a great way to encapsulate the state with behavior to keep the state valid. Using factories to create your aggregates is key to having a valid state from the very beginning. Here’s how you can create an always valid domain model. 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… Read More »ALWAYS Valid Domain Model