Time for the second afternoon session here at CodeMash. This session is called Domain Driven Design and is being given by a gentleman by the name of Barry Hawkins. This is the second presentation I’ve seen Barry give today, he’s a very dynamica and entertaining speaker, but still is very on point.
The presentation focused on the importance of modeling. To distill this greatly models are a representation of the domain, the domain is the subject matter itself. It is important to use ubiquitous language across a team made up of all people necessary to move project from conception to completion. This means that subject matter experts and scenarios they provide feed the domain vocabulary, not pattern and practice leanings.
Domain models should start small and be validated by detailed reference scenarios. Barry’s team uses nNuit or jUnit to create tests to in effect ‘model’ the reference scenarios so they can validate the model accurately reflects them. The reference scenarios get increasingly complicated and are provided by domain subject matter experts. Barry used an example from the shipping industry as an example.
Another importance concept was to entertain different models, don’t settle on the first solution you think of. Use natural language to pseudo code out multiple modeling options to decide which is best for the context you’re in. Don’t be afraid to throw out models if they don’t work, the first thing isn’t the best thing necessarily.
Barry works with Eric Evans who authored a book, Domain Driven Design, which the talk was based on. Great overview of a very deep topic. I’m looking forward to picking up the book and learning more.