In the software industry, legacy code is a phrase often used as a negative by engineers and pundits alike to describe the anchor around our collective necks that prevents software from moving forward in innovative ways. Perhaps the correlation between legacy and stagnation is not so obvious—consider that all code is legacy code as soon it is used by customers and clouds alike.

Legacy code is everywhere. Every bit of software we use, whether in an app on a phone, in the cloud, or installed on our PC is legacy code. Every bit of that code is being managed by a team of people who need to do something with it: improve it, maintain it, age it out. The process of evolving code over time is much more challenging than it appears on the face of it. Much like urban planning, it is easy to declare there should be mass transit, a new bridge, or a new exit, but figuring out how to design and engineer a solution free of disruptions or worse is extremely challenging. While one might think software is not concrete and steel, it has a structural integrity well beyond the obvious.

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