Domain Language Newsletter
Current Issue: How do you get started with DDD when you are tied to a legacy, Part 3
In our current newsletter, Eric Evans continues his series about pragmatic techniques with context boundaries, anticorruption layers and a few other things.
Some legacy systems have very useful capabilities that are very difficult to use. Strategy 3 uses services and anticorruption layers to get at that good stuff.
Both types of bubbles (Strategies 1 and 2) create a context for developing a DDD application while coexisting with legacy systems. The next strategy flips this around, focusing on making the assets of the legacy more available for new application development, possibly in multiple contexts.
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March 2012: Getting Started With DDD When Surrounded By Legacy Systems. Part 2: Autonomous Bubble
Strategy 2, the "Autonomous Bubble", frees the development team to write innovative software that is not so sharply constrained by the legacy design as the bubble context (Strategy 1). An autonomous bubble can enable new software to have a product focus without commiting to major legacy replacement, although there is more architectural risk than with the previous strategy. Read »
June 2011: Getting Started With DDD When Surrounded By Legacy Systems. Part 1: Bubble Contexts
A DDD pilot project does not require a risky rearchitecture, yet can provide a lot of value. Choose an important, yet modest-sized, business related problem with some intricacy, and cherry-pick a team that has control over its code. The "bubble" isolates that work so the team can evolve a model that addresses the chosen area, relatively unconstrained by the concepts of the legacy systems. Read »
January 2011: Reflecting on a Good Year & What Comes Next
Cloud, Functional, Mobile ... Things change. How is DDD still relevant and how do we do it now? By Eric Evans Read »
September 2010: Eric Evans on Four Prerequisites of DDD
While the Strategic Design techniques of DDD can be applied in many situations, development based on subtle domain models has some demanding prerequisites. If you don't have them, it is a waste of effort to leap into application of DDD at the tactical level.
Instead of grinding your gears trying to express elegant models, you'd do better to direct your efforts toward establishing these conditions for success. Read »
July 2010: Eric Evans on DDD Exchange 2010
In 2010 the community's attention is turned toward two areas of innovative energy: A family of architectural approaches that promise to scale DDD more effectively; and a new look at fitting DDD and Agile processes together along with other key best practices.
Read Eric's thoughts on this one-day conference focuses on DDD hot topics of 2010: Event Sourcing, combining DDD with Agile and other processes, a fresh case study from a DDD project at Beasly Insurance, and more.Read »
March 2010: Eric Evans on Domain Events
Entities and value objects have a new mate. Eric lays out the Domain Event pattern, how it clarifies models and opens the door to new architectures.Read »
December 2009: Eric Evans and Michael Feathers
When to try to fix the legacy and when to break away? How do bounded contexts come into it? Eric and Michael had quite a conversation at the Silicon Valley Patterns Group meeting.Read »
September 2009: Report on the First DDD eXchange
A one-day conference dedicated to DDD.Read »
May 2009: First Newsletter. US Classes Launch!
Read »