Kill It with Fire

We know that past the upper bound of mere exposure, once people find a characteristic they do not like, they tend to judge every characteristic discovered after that more negatively. 17 So programmers prefer full rewrites over iterating legacy systems because rewrites maintain an attractive level of ambiguity while the existing systems are well known and, therefore, boring. It’s no accident that proposals for full rewrites tend to include introducing some language, design pattern, or technology that is new to the engineering team. Very few rewrite plans take the form of redesigning the system using the same language or merely fixing a well-defined structural issue. The goal of full rewrites is to restore ambiguity and, therefore, enthusiasm. They fail because the assumption that the old system can be used as a spec and be trusted to have diagnosed accurately and eliminated every risk is wrong.