Hey Boss, look here!
I made a magical X-ray app that displays our code as wiring.
Here is the shiny, neat program that Bob wrote 15 years ago, right before he left us:
And here is what it is today, after Tom took it from Bob, and Jane from Tom, and Mick from Jane, and me from him, porting it to roughly four new platforms, and adding about 240 features from customer requests (150 of which were urgent):
"Technical debt" is a phrase that was invented to explain the phenomenon in a way that bean-counting business bosses could understand: we can do it this way in a way that costs us less today but will incur a debt that will slow us down in the future. It was always an attempt to quantify the concept in a way that we have to think about tradeoffs between our current resources and our future resources.
The only problem is that technical debt in software is not visible.