Know the interest.
Ward Cunningham coined “technical debt” in 1992. Martin Fowler's quadrant shows that not all debt is taken on the same way.
Deliberate and prudent
“We'll ship now and fix it properly next sprint.” A conscious trade-off.
Deliberate and reckless
“No time for design.” Shortcuts nobody plans to fix.
Inadvertent and prudent
“Now we know how we should have built it.” Learning shows the debt.
Inadvertent and reckless
The team didn't know good practice. Debt nobody noticed taking on.
Source: Ward Cunningham: The WyCash Portfolio Management System ↗
Know the interest. Pay the expensive debt first.