Studying for AZ-204: Developing Solutions for Microsoft Azure I’m scheduled to take the AZ-204 exam in the next couple of weeks so I’m currently playing around with the main resources covered to get some practice in the portal and also writing client code to use the resources. Today I’m having a go at creating a NoSQL database in…

Introduction Understanding Dependency Inversion has been a long journey for me. I quickly understood Dependency Injection as it gained popularity and, as somebody who likes automated unit tests, could immediately see benefits of using it for testing. What is Dependency Inversion though and how does it differ from Dependency Injection? In…

Introduction The Single Responsibility Principle is the most misunderstood of all the SOLID Principles. I’ve certainly gotten it wrong in the past and almost everybody I talk to gets it wrong in the same way. How can that be when it seems like the simplest principle? Granted, not all people get…

Measuring Coupling and Cohesion of Bounded Contexts on an EventStorming Domain Model EventStorming A great way to design Event Sourced Domain Models following a DDD approach is Alberto Brandolini’s EventStorming. In an EventStorming workshop, Software Developers and Domain Experts talk about the Domain and map it out using sticky notes. They start by adding an Orange sticky note for each event that occurs…

Commands are complex, Queries are simple Previously we’ve looked at DDD Entities, that have state, and Events, where state changes. To reduce complexity we can be specific about what has state and encapsulate where it changes. Events are high level code, sitting in the middle of the Onion Architecture. In this article, we will look at…

Why do Events matter so much in Domain-Driven Design? The Evolution of Events in Domain-Driven Design Most aspects of modern software engineering can be found in or traced back to Domain-Driven Design: Tackling Complexity in the Heart of Software by Eric Evans. EventSourcing is something that has evolved in the world of DDD practitioners and has become more mainstream in recent years. …

What are Entity and Value Types in Domain Driven Design? In Domain-Driven Design: Tackling Complexity in the Heart of Software by Eric Evans, Entity and Value Types are 2 of the fundamental building blocks that the concepts in the rest of the book are built on. Let’s take a look at what they are and why they matter. Entities In DDD…

Everybody asks for TDD but nobody uses it. We’ve all interviewed at companies for Software Developer roles where Test Driven Development (TDD) is pushed as common practice at the company and is stipulated in the role spec. Most do. …

What advice would you give your younger self? This is a question I often see asked. I honestly think at this point in life the best advice I could give my younger self is that I am wrong more than I think I am. Perspective comes from time and experience Sometimes I quickly realise I’m wrong during or shortly after a discussion and it’s…