Technical Debt: Rank a Backlog

Score each backlog item on interest rate, change frequency, blast radius and remaining life, and rank the list by what is actually worth repaying. Interest and frequency multiply, so debt in code nobody touches sinks to the bottom where it belongs.

Rank Item Interest Frequency Blast Life Priority Verdict Remove

What the dimensions mean

Interest rate
Hours lost per change, incidents per quarter. Rough is fine — written down is the point. 1 — Costs nothing to work around 5 — Every change pays a tax
Change frequency
Straight from version-control history, not from memory. This is the hotspot axis. 1 — Untouched for a year 5 — Changes most weeks
Blast radius
How far a failure or a breaking change travels. This is what turns quality into risk. 1 — One team, one component 5 — Many teams depend on it
Remaining life
How long you will keep paying the interest. Nothing is worth repaying on a component you are about to delete. 1 — Being retired within a year 5 — Load-bearing for years yet

Priority = ((interest + blast) ÷ 2) × frequency × life, as a share of 125. Change frequency and remaining life multiply because each is a condition, not a weighting: debt in code nobody changes charges nothing, and nothing is worth repaying on a component you are about to delete. Interest and blast radius are averaged — both are how bad it is, and a one-team component with a daily tax is still worth fixing.