Strategic Domain Driven Design Tools for Non-DDD People

DDD has a reputation for being esoteric and hard to grasp for newcomers. So the community has been working hard to simplify the user experience for people new to DDD by providing practical tools like the Bounded Context Canvas which even people with no prior DDD experience can benefit from to design loosely-coupled microservices. These tools will provide you with instant value. You can use them right away on the systems you are building. The tools also help you on the path to mastery of DDD. And all of the tools are open source and creative commons, so nobody is trying to sell you anything.

DDD Video

Feb 8 2023

 Aligning Bounded Contexts with Subdomains in Legacy Code

One way or another, each system contains some kind of boundaries. I would go so far and claim that even the dreaded Big Ball of Mud systems consist of parts that could be perceived as separate though undoubtedly only under deep scrutiny. The difference is in the “thickness” of the boundaries and the measure of interrelationships between the different parts of the system, the frequency and amount of data that is passed across the fences. It is the latter that leads to increased coupling resulting in systems that are hard to maintain and hard to change. This presentation will present a story of an attempt to achieve an alignment between perceived subdomains, logical boundaries and source code structure in a legacy system. Based on the use case from healthcare we will go into technical detail on concrete steps that were followed to create a new bounded context using strategic Domain-Driven Design and 4+1 Architectural View Models.

Architecture DDD Design Video

Dec 22 2022

 Balancing Coupling in Software Design

We are used to treating coupling as the necessary evil. Hence, we aim to break systems apart into the smallest services possible, in the ever-lasting quest of decoupling everything. But what results are we getting by following this reasoning? — Instead of the promised land of evolvable systems, many such “decouple everything” endeavors lead straight into the chains of distributed monoliths. Can we do better? What if there is a better way to handle coupling in distributed systems? Or even, what if instead of fighting coupling, we can use it as a heuristic for designing systems that are actually evolvable and maintainable? That’s exactly what you will learn in this session: what coupling is, and how you can use it as a design tool. We will start by taking a journey through time, and explore the different models of evaluating coupling. Next, we will combine the existing knowledge into a coherent model — a simple function for evaluating a system’s decomposition into components. This function will allow you to assess the expected effort for evolving a system and use it as a heuristic for optimizing architectural design decisions.

DDD Design Video

Dec 22 2022

 Clean Architectures in Python

Architectural considerations are often overlooked by developers or completely delegated to a framework. We should start once again discussing how applications are structured, how components are connected and how to lower coupling between different parts of a system, to avoid creating software that cannot easily be maintained or changed. The ""clean architecture"" model predates Robert Martin, who recently brought it back to the attention of the community, and is a way of structuring applications that leverages layers separation and internal APIs to achieve a very tidy, fully-tested, and loosely coupled system. The talk introduces the main ideas of the architecture, showing how the layers can be implemented in Python, following the content of the book ""Clean Architectures in Python"" edited by Leanpub. The book recently reached 25,000 downloads and many readers found it useful to start learning how to test software and how to structure an application without relying entirely on the framework.

Architecture DDD Python Video

Nov 13 2022

 Strategic Domain-Driven Design

If you’re a software developer or architect who wants to play a more influential role in ensuring your software systems are optimised to support business goals, then you need to learn about the benefits and techniques of modern strategic domain-driven design. Many people think that DDD is about software design patterns, but that’s only a small part, and the least important part of DDD. In fact, Eric Evans wishes he’d focused more on the strategic aspects of DDD in his famous book (Domain-Driven Design: Tackling Complexity in the Heart of Software) and pushed the tactical coding patterns to the back! Strategic domain-driven design is about truly understanding the business domain. It involves collaboratively modelling business processes using advanced modelling techniques, like Event Storming and Domain Storytelling, with domain experts on an ongoing basis. One of the core outcomes of strategic DDD is identifying cohesive modules, known as bounded context. Bounded contexts help you to create a maintainable, comprehensible codebase by isolating dependencies and delineating concepts that reference different classes of business value. In this talk, you’ll see many of the most effective bounded context design heuristics, recurring patterns in the wild, and you’ll learn how to facilitate those vital modelling sessions so you can lead the adoption of strategic DDD in your organisation.

DDD Design Video

Mar 20 2022

 The Pillars of Domain-Driven Design

Domain-Driven Design is neither a method nor a technology, it is a culture, a way of thinking about the needs of the customers first and putting an emphasis on their language and human interactions. The promise of DDD is to tackle complexity in the heart of software, and the means are plentiful and can be overwhelming. There are three pillars though, on which the whole approach stands. A focus on learning, language, and empathy. With the right mindset, it becomes simple to derive good models, keep them pure and aligned with the business. Simple is not easy, but done right Domain-Driven Design transforms everything in your organization from code to culture, from agile to architecture.

DDD Event Sourcing Video

May 16 2021

 Modeling Uncertainty • Vaughn Vernon

The foundation ideas behind Domain-Driven Design, or DDD, are fundamentally the same as when Eric Evans brought them to our attention through his seminal work. The Bounded Context with its Ubiquitous Language is still of chief importance, along with mapping various Bounded Contexts to form a whole system solution. Even so, what has changed substantially is the computing landscape on which software developers construct and release these solutions. Systems are far more likely to be distributed, especially due to the [...]

Architecture DDD Video

Jun 24 2020