Software decay is a key concern for large, long lived software projects. Systems degrade over time as design and implementation compromises and exceptions pile up. However, there has been little research quantifying this decay, or understanding how software projects deal with this issue. While the best approach to improve the quality of a project is to spend time on reducing both software defects (bugs) and addressing design issues (refactoring), we find that design issues are frequently ignored in favor of fixing defects. We find that design issues have a higher chance of being fixed in the early stages of a project, and that efforts to correct these stall as projects mature and code bases grow leading to a build-up of design problems. From studying a large set of open source projects, our research suggests that while core contributors tend to fix design issues more often than non-core contributors, there is no difference once the relative quantity of commits is accounted for.