Technical debt is not a problem — it's a management tool. Well understood and managed, it enables fast delivery without mortgaging the future. Poorly managed, it paralyzes teams.
The technical debt metaphor, coined by Ward Cunningham, is often misunderstood. Debt isn't necessarily the result of poor practices — it's sometimes a deliberate and rational choice. Quickly delivering an imperfect solution to validate a market, then repaying the debt once value is confirmed, is a perfectly valid strategy. The problem is unintentional and untracked debt.
To measure debt, tools like SonarQube provide objective metrics: code smells, duplications, cyclomatic complexity, test coverage. These metrics give a partial but useful picture. The SQALE method (Software Quality Assessment based on Lifecycle Expectations) goes further by estimating remediation cost in person-days. This figure, compared to current maintenance cost, helps prioritize repayments.
Debt management must be tooled and visible. A Tech Debt Backlog maintained by the technical team, regularly discussed with the Product Owner, is the most effective practice. Allocating 20% of each sprint's capacity to debt repayment is an empirical rule that works well. What matters is that debt isn't invisible — documented and prioritized debt is manageable, hidden debt is a time bomb.
→ See also: SOLID principles · Clean Architecture