Technical debt: The silent killer of your software

Technical debts are like a loan you will receive in the future of your software. Short-term abbreviations and compromises in the code may save time today.

However, they accumulate interest rates in the form of increased maintenance effort, decreasing development speed and increasing susceptibility to errors.

Untreated technical debt can drive a software project into ruin.

What are technical debts?

The term "Technical Debt" was coined by Ward Cunningham in 1992.

It describes the implicit costs that arise when developers choose fast but suboptimal solutions instead of implementing the best solution.

As with financial debt, the longer the debts are, the more expensive their eradication will be.

What you see (10%)

Technical debt can ruin your software project.

For Technical debt: The silent killer of your software, Cost Calculator: AI Development, Solution: Legacy Reduction, Software Maintenance sowie Cost Calculator: Software Maintenance help you align rollout, scope and budget before you commit.

Visible bugs, slow performance, outdated user interface

What's underneath (90%)

Missing tests, outdated dependencies, undocumented code, bad architecture, vulnerabilities, duplicated code

The different types of technical debt

Code debt Duplicated code, missing abstraction, complex methods, unclear naming

Architectural schools Monolithic structures, lack of modularity, close coupling between components

Test schools Missing unit tests, no integration tests, insufficient code coverage

Documentation schools Outdated or missing documentation, unclear API descriptions

The true cost of technical debt

Technical debts are not just a technical problem – they have massive business impacts:

ImpactDescriptionCosts Slower development New features last longer than 30-50% development time Increased error rate Changes lead to unexpected bugs+40% bug fixes Employee turnover Good developers leave frustrated the team 50-200% of the annual salary per leaving Safety risks Old dependencies with vulnerabilitiesPotential catastrophic

"Technical debts are like weeds in the garden. If you do not regularly ask, it will eventually overthrow everything."

Strategies for reducing technical debt

The Boy Scout rule: Always leave the code a little better than you found it. Small, continuous improvements add up.

• Dedicated Refactoring-Sprints: Regularly reserve time (e.g. 20% of each sprint) exclusively for the removal of technical debt.

• Building backlog lead: Document They systematically and prioritize technical debt after impact and effort.

• Automatized code review: Use tools like SonarQube to measure and monitor technical debt.

• Test Driven Development: Write tests before the code to ensure high quality from the start.

When is professional help necessary?

If the technical debts are so high that the team has more time with failure

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On the numbers: Survey and market figures without an inline footnote follow common public reports (e.g. Bitkom) and official statistics (Destatis). Practical examples: Groenewold IT internal data, 2026.

References and further reading

The following separate references complement the topics in this article:

• Bitkom – German digital industry association.
• German Federal Office for Information Security (BSI).
• European Commission – Digital strategy.
• MDN Web Docs (Mozilla)
• W3C – World Wide Web Consortium.

"Privacy by design is an architecture issue—especially when master data is personal."

— Björn Groenewold, Managing Director, Groenewold IT Solutions

Frequently Asked Questions (FAQ)

What is this article about: “Technical debt: The silent killer of your software”?

Here we cover Technical debt. The silent killer of your software — focused on architecture, process, and business outcomes. In short: Technical debt can ruin your software project.

Learn how to find, measure and systematically reduce them.

Who benefits most from the content described here?

Typical readers are business and IT leaders in Software maintenance who want to secure quality, security, and ease of upkeep over the long term.

How does this topic fit into an IT or digital strategy?

In a digital strategy, prioritize stable core processes first, then extensions. See also professional software development and consulting.

For multi-system landscapes, IT consulting and architecture helps align vendors and internal teams.

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