Adoption of DDD

DDD has remained popular since its inception, as depicted in the following screenshot, which shows a trend line in a Google Trends graph.

Figure 1.2 – Google Trends graph of searches for DDD

Indeed, it is just as valuable to learn DDD (maybe more so) now as in 2004 (as far back as Google Trends goes).

Although Evans laid the foundation for DDD, it has remained relevant for nearly 2 decades because, in Evans’s own words, “smart and innovative people have shaken things up repeatedly.” These people have taken the fundamentals outlined in a DDD and created new concepts, which have enabled DDD to remain relevant, even though the way we write software has changed quite dramatically.

Some of the books highlighted by Evans are listed here:

• Greg Young and his work on Command Query Responsibility Segregation (CQRS): CQRS is a pattern that emerged to capture all application changes as a sequence of events. It allows the segregation of read and write events from the database and can help maximize application performance, scalability, and security. This is particularly popular in large enterprise software.
• Domain-Driven Design Quickly: This book was released in 2006 and was (and still is) free; you can read it here: https://www.infoq.com/minibooks/domain-driven-design-quickly/. Evans likes this book as its simple and succinct nature made DDD accessible to everyone.
• Vaughn Vernon and his book Implementing Domain-Driven Design: Evans described Vernon’s book as “the most ambitious book since my own.” The community has affectionately called this book the Big Red Book. This book refreshed a lot of the ideas that Evans outlined originally and focused more on how you can implement DDD.

Big companies such as Microsoft, Amazon, and IBM use DDD internally and guide how you can use it too. It is, therefore, still a great time investment to learn about DDD today.

Is DDD always applicable though? Just because big companies use it, it does not necessarily mean it is a good fit for your side project. In the next section, we explore this in more detail.