Good reminder of why "tech debt" is not a so bright metaphor. I find it useful sometimes but clearly it became overused in the industry (often a sign of something loosing its meaning whatever it was). That's why lately I'm talking about complexity, some of it being legitimate so you need to keep the illegitimate one at bay. I like the focus on maintenance in that post. Also there are a couple of good ideas on how to schedule the maintenance tasks in your project.