One of the main contributor to keeping business easy to respond to change is maintainable software. On the opposite, it is possible to cripple the business by creating unmaintainable software. Like a garden, the nature of software development tends to decay code that requires an increasing amount of time to understand the code than writing it. What can we do? This talk shares the impact of unmaintainable software and how to deal with it through the developer skill of code smells & refactoring.