A team's backlog contains fifty technical debt items. How should they be triaged, and which category is most often mis-sorted?

The triage axes

Interest rate and principal, borrowed deliberately from the metaphor:

• Interest rate: how much this costs per unit time, in slowed delivery, incidents, or engineering frustration. A shortcut in a module nobody touches has an interest rate of approximately zero.
• Principal: how much it would cost to fix.

High interest and low principal is the obvious priority and it is where most of the available value is. High interest and high principal is the strategic decision. Low interest and low principal is the tempting distraction — cheap, satisfying, and worth almost nothing. Low interest and high principal should be documented and left alone.

The category most often mis-sorted

Code that is unpleasant but stable and untouched. It attracts attention because it is visible and offends engineering sensibility, and its interest rate is near zero because nothing changes there.

A module untouched for four years is not a debt problem however unpleasant it looks. Change history is the evidence, and it takes minutes to gather.

What is systematically under-recognised as debt

• Missing tests on frequently-changed code, which is high interest because it taxes every change.
• Slow feedback loops — a build, a test suite, a deployment — which tax every change by every engineer and compound across the team.
• Undocumented behaviour that only one person understands, which is a risk with a deadline set by that person's departure.
• Operational debt: manual processes, missing alerts, unexercised runbooks. Frequently the highest interest rate in the estate and rarely on the list, because it is not code.

The structural requirement

A protected allocation rather than per-item negotiation. Debt work loses every individual comparison against a feature with a named customer, reasonably, and the aggregate outcome — none of it done — is nobody's decision.

A fixed proportion, owned by the team, reported like any other work. Owned by the team because they hold the information about where the interest actually is.