In almost every conversation I’ve had with Eric Evans and Jimmy Nilsson and every talk I’ve heard Eric present, the same message have been lifted; “I wish I put part 3 [strategic design] in the beginning of the book”. In this talk he explained why.
ent on mentioning a few other mistakes people do:
- Building a platform to make the other (lesser) programmers more productive. If they are [lesser] chances are they can’t use the platform anyway.
- Cleaning up other peoples mess. (Invisible value). One irresponsible programmer can keep 5 really good programmers busy cleaning up.
- Rebuilding already working software, delivers visible value, but will it deliver any new sexy value?
- The Enterprise Model
In Eric’s opinion there are really bad consequences for a bad strategy and most of them are tied into information not floating to the surface. He lifted up a really good example where a programmer warns about potential data-corruption that someone else introduced, sits up all night to fix it, and when there is no data corruption; management will turn to the fixer and say “see, no problems you where just crying wolf”.
What’s a responsible designer to do?
In the talk, Eric highlighted three strategies from his book that we should focus on to create a great strategy.
Distilling the core Domain
There is always a reason for building custom software. Something makes it hard to but it off-the-shelve. This is the core domain. This is the difference between what you do and what others do. Sometimes it’s easy to find, other times it’s not as easy. The point is that it’s in the core domain the interesting stuff is happening, where the new sexy features get implemented.
Context Mapping / Bounded Context
For this part the message was clear; “There will always be more then one model”. He gave the example of The Blind Men and The Elephant. Not everyone will look at things in the same way and context is very important.
This is a strategy where you hide away the bad design with a layer above it that straightens it out a bit, build your new features on top of that piece.
Good Strategic Goals,
A picture says it all,
Strategic design it is my favorite part of Evan’s book. It helps us understand how to look ahead and make sure that our shiny new toy shines all the time. I’ve seen this talk before but it’s like the book, every time I see it there is a new point made that I didn’t thing about before. This time the focus on the core domain really sunk in and I immediately realized why we’ve hade problems in our current project and in a couple of earlier.