ActiveEngine Sensei’s Mother Comes to Visit – Lessons in Design Patterns

For Thanksgiving Sensei’s mother came to visit the dojo, but this time she brought a new addition to the family, her dog. This puppy is lovable enough, and like all puppies needs training, which Sensei felt compelled to provide. When Sally got out of line and starting biting, Sensei held her down gently but firmly around the collar bone. This is an old trick that Cesar the Dog Whisperer practices with the smaller dogs – firm, gentle and consistent.

After two times, Sally stopped nipping at Sensei. “Wow, that really works quickly”, Sensei’s mother says.

“It’s easy to do, here’s how, ” and he showed her. The next time Sally started nipping, Sensei’s mother repeated the maneuver many times and lo and behold, Sally learned to not bite.

There are some lessons to be learned here for those who wish to practice Agile, Test Driven Development and implement design patterns: you must learn good technique from good practitioners, then repeat, repeat, repeat while seeking feedback. There’s no short cut to internalizing execution, and certainly no short cut to understanding when and why to apply design patterns. This begs the question for senior team members when do you make design decisions and what justification can you convey to junior team members concerning your choices?

Sometimes this can be very easy. The decorator pattern is a great example, as the justification answers the question of “I have many variations to accommodate in a billing process, and do not want a proliferation of classes or difficult logic to support all the exceptions.” To make this connection between technical implementation with business requirements takes practice, and the articulation of the justifications is a great way to obtain fluency. Repetition and review and those key ingredients that help create a powerful ActiveEngine toolkit.