Technical Debt: How to Measure It and a Realistic Plan to Pay It Down

Every software team takes shortcuts. A deadline looms, a quick fix ships, and a design that suited ten users has to serve ten thousand. That is technical debt: the gap between the system you have and the system you would build with hindsight. Like financial debt, it is not automatically bad. Borrowing to ship sooner can be a smart decision. The danger is paying interest forever without noticing.

What technical debt looks like

• Code debt: tangled, duplicated or poorly named code that is hard to change safely.
• Architecture debt: a structure that no longer fits the product, such as a monolith everyone is afraid to touch.
• Test debt: missing or unreliable automated tests, so every change feels risky.
• Dependency debt: frameworks and libraries left far behind their supported versions.
• Documentation and knowledge debt: critical understanding held in one person’s head.
• Infrastructure debt: manual deployments and fragile servers nobody dares rebuild.

Signs your technical debt is costing too much

• Small changes take far longer than they should.
• Bugs keep returning, or fixing one thing breaks another.
• New engineers take months to become productive.
• Releases are rare, stressful and followed by hotfixes.
• Engineers say a certain part of the system is the one nobody wants to touch.
• Estimates keep growing for work that sounds simple.

How to measure technical debt

There is no single number for technical debt, but a mix of signals gives a useful picture.

1. Ask the team. A simple survey or workshop that maps pain points to parts of the system is surprisingly effective. Engineers know where the problems are.
2. Look at delivery metrics. Lead time for changes, deployment frequency and the share of time spent on unplanned work all reflect hidden debt.
3. Find the hotspots. Files that change often and also attract many bugs are the most expensive places to carry debt. Version control history makes them easy to find.
4. Use code analysis tools. Measures such as complexity, duplication and test coverage are imperfect, but trends over time are informative.
5. Track incidents. Repeated outages caused by the same weak spot are a clear price tag.

Deciding which technical debt to fix first

Not all debt deserves repayment. Rank it by two questions: how much does it slow us down or put us at risk, and how often do we work in that area? Debt in code that rarely changes can sit quietly. Debt in the heart of the product, touched every week, is costing you daily. Then weigh the effort. Quick wins in high-impact areas go first.

A realistic plan to pay down technical debt

• Reserve capacity. Set aside a steady share of every cycle for improvement work. A fixed allowance works better than a promised big clean-up that never gets scheduled.
• Improve as you go. When a change touches messy code, leave it a little better than you found it.
• Write tests first. Before restructuring risky code, add tests that pin down its current behaviour so you can change it with confidence.
• Replace gradually. For large structures, build the new piece beside the old one and move functionality across step by step, rather than attempting a risky rewrite.
• Automate the boring parts. Automated formatting, dependency updates and deployment remove whole categories of friction.
• Stop new debt where you can. Code review, agreed standards and a clear definition of done prevent the problem from growing faster than you repay it.

Talking about it with the business

Non-technical stakeholders respond to impact, not jargon. Instead of asking for time to refactor, explain what it will change: shorter delivery times, fewer outages, faster onboarding, lower risk. Tie each piece of repayment to an outcome the business already cares about, and report the effect once you finish.

Deliberate versus accidental debt

Not all technical debt is a mistake. Deliberate debt is a conscious trade: ship a simpler version now to meet a launch date or test an idea, with a plan to improve it later. That can be an excellent business decision when the team records the trade-off and schedules the follow-up. Accidental debt is different. It builds up unnoticed through rushed work, unclear requirements or gaps in experience, and nobody chose it.

The healthiest teams make deliberate debt visible. When they take a shortcut, they write down what they skipped, why, and what it will cost to fix. A short note in the backlog is enough. Debt you record can be planned for, while debt you forget simply compounds.

Debt you should not repay

It is tempting to treat every untidy corner as something to fix, but repayment has a cost too. Some debt is not worth paying:

• Code that is stable and rarely changes. If it works and nobody touches it, leave it alone.
• Systems about to be retired. Improving something you will replace next quarter is wasted effort.
• Cosmetic issues. Naming preferences and style differences matter far less than structural problems.
• Experimental work. A prototype you may discard does not need production polish until the idea proves itself.

The question to ask is always whether fixing it would measurably improve speed, reliability or safety. If the answer is no, spend the time elsewhere.

A worked prioritisation example

Imagine a team that lists four problems. The checkout module is tangled, changes weekly and caused two incidents last quarter. The reporting module is also messy, but it changes once a year and has never failed. Meanwhile, the build takes forty minutes and every engineer waits for it daily. And the framework version is two releases behind but still supported.

A reasonable ranking puts the slow build first, because it taxes every person every day and is usually cheap to improve. The checkout module comes second because it is high-risk and frequently touched, and you can improve it gradually, adding tests around each change. Next, the team schedules the framework upgrade before support ends. They leave the reporting module alone. You need no complex scoring, only an honest look at impact, frequency and effort.

Practices that stop debt from piling up

• Definition of done. Include tests, documentation and review in what counts as finished, so quality is not optional under pressure.
• Code review. A second pair of eyes catches problems while they are cheap to fix, and spreads knowledge across the team.
• Automated checks. Linters, formatters and tests enforce standards without relying on memory or goodwill.
• Regular dependency updates. Small, frequent upgrades are far easier than rare, large ones.
• Architecture decision records. Short notes explaining why the team made important choices stop people undoing or repeating them by accident.
• Healthy scope management. A realistic plan reduces the pressure that leads to avoidable shortcuts.

Common questions

Should we stop feature work to fix technical debt?

Rarely. A long freeze is hard to justify to the business and often fails to finish. Steady, planned improvement alongside feature work is more sustainable and keeps value flowing.

Is a rewrite the answer to heavy technical debt?

Occasionally, but it is usually the riskiest option. Gradual replacement, where new components grow beside the old ones, tends to be safer and delivers value sooner.

How do we know if we are improving?

Watch the trends: shorter lead times, fewer incidents, less unplanned work, and faster onboarding for new engineers. If those move in the right direction, the repayment is working.

Carrying some debt is normal. Ignoring it is what turns a healthy product into one that cannot change. If your system has become hard to evolve, our team can help you assess it and plan a safe path forward. Learn about our custom software development services or speak with an engineer.