Insights Business| SaaS| Technology Why Some Bugs Are Worth Millions to Leave Unfixed
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Oct 24, 2025

Why Some Bugs Are Worth Millions to Leave Unfixed

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James A. Wondrasek James A. Wondrasek
Graphic representation of the topic Why Some Bugs Are Worth Millions to Leave Unfixed

You’re looking at your bug tracker. It’s got 127 open issues. Your developers want to fix them. Your product manager is pushing for new features. Your CFO is asking why engineering costs keep climbing.

Here’s what experience teaches: not every bug deserves fixing. Some cost more to fix than they’ll ever cost to leave alone.

Engineering resources are limited. Every hour spent fixing a minor bug is an hour not spent building features that drive revenue. You need frameworks for deciding which bugs warrant attention and which ones get filed under “won’t fix” with a clear conscience.

This article explores a counterintuitive aspect of the hidden economics of technical decisions – specifically, strategic technical debt management. We’ll walk through five scenarios where bugs become economically irrational to fix, show you the maths for calculating fix ROI, and give you the language to defend these decisions to stakeholders who think “broken” automatically means “must repair”.

What Makes Some Software Bugs More Expensive to Fix Than to Leave Unfixed?

Calculate the fix cost. Then calculate the impact cost. If fix exceeds impact over the bug’s expected lifespan, you’ve found a bug worth leaving alone.

Fix costs include developer time, QA cycles, deployment overhead, regression risk, and documentation updates. But the biggest cost is opportunity – the feature work you’re not doing while fixing bugs. Research shows engineering teams allocating 25% of their workweek to technical debt still struggle to keep up when they can’t say no strategically.

Impact costs are different. They’re support tickets multiplied by resolution time, user friction that might or might not show up in churn metrics, and the workarounds your team maintains.

Take this example. You’ve got a bug in a rarely-used export feature. It affects maybe 5 users per month who each lodge a support ticket. Your support team has a documented workaround that takes 10 minutes to explain. Total monthly impact: about 50 minutes of support time.

The fix requires touching a fragile legacy component. Your senior developer estimates 2 weeks to fix it properly, plus another week for testing. That’s 3 weeks of engineering time that could go toward the feature roadmap instead.

Do the maths. The bug costs you maybe 10 hours per year in support time. The fix costs 120 hours upfront plus the risk of introducing new bugs in a system that currently works. Unless you’re planning to maintain this product for more than a decade, fixing makes no economic sense.

Technical debt only becomes a problem when it impacts business value, according to AI Product Manager Sri Laxmi. The bugs worth fixing are the ones slowing development, increasing defects, or introducing risk to revenue-generating features.

Use this threshold: if fix cost exceeds 3 years of impact cost, seriously consider leaving it unfixed.

How Do Bugs Create Competitive Advantages or Technical Moats?

Your customers adapt. They build workflows around your product’s actual behaviour, bugs included. When they invest months integrating with your API or training staff on workarounds, you’ve accidentally created switching costs.

This pattern is common. Quirky behaviour that customers document in their internal wikis. Undocumented API endpoints they discovered and built workflows around. Performance characteristics that accidentally optimise for their specific use case.

Think about those quirky behaviour patterns customers document in their internal wikis. The undocumented API endpoints they discovered and built entire workflows around. The performance “bugs” that accidentally optimise for their specific use case.

Consider a validation bug that allows customers to import data in a non-standard format. Hundreds of customers have built automated import scripts that rely on this leniency. Your competitor’s product has “correct” validation that would reject these imports.

Fixing your bug costs customer goodwill and creates an opportunity for competitors while your customers curse you for breaking their automation. Shadow IT ecosystems emerge around older systems, according to Martin Fowler’s research.

Sometimes the strategic move is preserving the bug deliberately. When the competitive value of customer lock-in exceeds the technical debt burden, you document the quirk, maintain it carefully, and count it as a feature in your competitive moat strategy.

Why Would Fixing a Bug Break Backward Compatibility With Customer Workflows?

Customers don’t integrate with your intended behaviour. They integrate with your actual behaviour.

When you fix validation logic, you break every customer import script that relied on the old validation being lenient. When you fix timing issues, you break workflows built around those delays.

The pattern is predictable. A customer discovers your product has a bug. They can either wait for a fix or build a workaround. Waiting means their project stalls. Building a workaround means their project ships on time.

Six months later, that workaround is embedded in their production systems. Other teams in their organisation have copied the pattern. It’s in their deployment scripts, monitoring systems, and data pipelines.

Now you fix the bug. You announce it as an improvement. Your customer’s production systems break. They open urgent support tickets asking why you broke their integration.

API versioning keeps old and new behaviour running in parallel, routing clients to the appropriate version. But this doubles your maintenance burden. You can use feature toggles for gradual rollouts, schema evolution that adds fields without removing them, or compatibility layers that translate between formats.

All of these add complexity and cost. Sometimes the right answer is acknowledging that the bug has achieved functional feature status and treating it accordingly.

What Is the 80/20 Rule for Bug Prioritisation and Technical Debt?

Twenty percent of your bugs cause eighty percent of your customer impact. Find that 20% and fix it. Leave the rest alone unless they migrate into the high-impact category.

Often 20% of a codebase is responsible for 80% of development pain – recurring bugs, build failures, performance bottlenecks. The Pareto Principle applies beautifully to bug triage when you’ve got the discipline to use it.

This approach parallels how successful companies handle velocity trade-offs by focusing resources where they generate the most value. Systematic technical debt prioritisation requires the same discipline – identifying the critical 20% that drives 80% of the pain.

Start with severity classification. Bugs requiring immediate response need senior developers and DevOps team involvement. High priority bugs get a 4-hour response window. Medium priority bugs can wait 24 hours. Low priority bugs go into the next sprint and might never get fixed.

But severity alone doesn’t tell you which bugs to fix. You need a second dimension: fix cost. Build a matrix with impact on one axis (P0/P1/P2/P3) and fix cost on the other (High/Medium/Low). Plot every bug. The ones in the high-impact, low-cost quadrant get fixed immediately. The ones in the low-impact, high-cost quadrant get closed with documentation explaining why.

Triage is about making life better for users by basing decisions on actual usage data, according to developer Jeff Atwood. Error logs and usage analytics tell you which bugs users actually encounter versus which ones exist only in your test scenarios.

Pedro Souto, Vice President of Product at Rydoo, puts it simply: “I’ve seen far more ROI in targeting high-impact technical debt than in blanket code refactoring”. This 80/20 technical debt triage approach – outlined in our comprehensive prioritisation framework – forces strategic thinking instead of reactive firefighting.

How Can Bugs Function as Feature Gates in Freemium Business Models?

Some bugs in free tiers stay bugs. Others become reasons to upgrade.

Strategic usage limits include monthly API call caps that allow testing but fall short for production use. Rate limiting that works for evaluation but bottlenecks real applications.

The ethical boundary is clear: deliberately introducing bugs as feature gates damages user trust. Preserving existing bugs as natural segmentation between free and paid tiers is a strategic business decision.

Google Maps Platform provides $200 monthly credit for free tier users, letting developers do meaningful work while preventing abuse. That’s intentional limitation done transparently.

The better approach uses bugs to demonstrate premium value without explicit restriction. When your free tier has a bug that limits batch processing and your paid tier has the fix, you’re prioritising where engineering resources go. Free tier users hit the bug, calculate the workaround cost, and compare it against the upgrade price.

Stay on the transparent end of that spectrum. Drift toward deception and you’re building user resentment that will cost more than the upgrade revenue gains.

How to Calculate the ROI of Fixing a Bug Versus Leaving It As-Is?

Formula: (Annual Impact Cost – Fix Cost) / Fix Cost. This gives you a percentage showing return on every dollar invested in the fix.

Annual impact cost is straightforward. Support tickets per year multiplied by average resolution time multiplied by support hourly rate. Add user friction costs if measurable through churn or conversion impacts.

Fix cost includes development hours multiplied by developer rate, plus QA cycles, plus deployment risk quantified as probability of regression multiplied by potential regression impact. Don’t forget the opportunity cost of features not built.

Consider this example. Bug in reporting module affects 20 users monthly, generating 20 support tickets at 30 minutes each. Annual impact: 120 hours at $50/hour = $6,000.

Fix requires 80 developer hours at $100/hour = $8,000, plus 20 QA hours at $75/hour = $1,500, plus 10% regression probability requiring 40 hours = $4,000 expected regression cost. Total fix cost: $13,500.

ROI: ($6,000 – $13,500) / $13,500 = -55%. Negative ROI. You lose 55 cents on every dollar invested. Even over 3 years ($18,000), you’re barely breaking even.

Unless this bug is growing in impact or blocking major feature development, it’s a leave-unfixed candidate. Document the workaround, train the support team, and allocate those hours to features that generate revenue.

Edge cases exist. Regulatory bugs must be fixed regardless of ROI. Security bugs with reputational risk carry costs beyond support tickets. But for most bugs in your backlog, this ROI calculation gives you a defensible framework.

How to Communicate to Stakeholders Why We’re Not Fixing Certain Bugs?

Use business language, not technical excuses. Talk about investment, return, resource allocation, and strategic priorities. Quantify everything.

C-level conversations require business-focused ROI presentations oriented to strategic priorities. Your CFO doesn’t care about refactoring. They care about cost reduction, revenue enablement, and risk mitigation.

The template looks like this. “This bug affects 5 users per month with a workaround that takes 10 minutes to implement. Annual impact: 10 hours of support time at $500 cost. The fix requires 120 engineering hours at $12,000 cost plus regression risk. ROI is negative 95% even over 3 years. Those 120 hours could build Feature X that we’ve estimated will generate $50,000 in first-year revenue.”

When stakeholders push back with “but it’s broken”, you need the data ready. Severity classification showing it’s P3 (low priority). Support ticket volume showing minimal user impact. ROI calculation showing negative return. Alternative solution showing the workaround is documented and sustainable.

Create transparency around triage criteria. Publish your severity classification system. Explain your response time commitments for each priority level. Show the bug backlog categorised by the impact/cost matrix. When stakeholders can see the framework, they’re less likely to question individual decisions.

Use relatable analogies to help non-technical stakeholders understand why addressing some debt matters while other debt can wait. Present bugs as a normal part of development that requires strategic management, not emotional reactions.

For a systematic approach to these conversations, see our guide on how CTOs evaluate counterintuitive trade-offs, which provides frameworks for translating technical decisions into business language that resonates with stakeholders across your organisation.

Conclusion

Bug triage is a strategic economic decision, not a technical perfectionism exercise. The bugs worth fixing are the ones where fix cost delivers positive ROI through reduced support burden, improved development velocity, or protected revenue streams.

The bugs worth leaving unfixed are those where fix cost exceeds impact cost over realistic time horizons, where customer workflows depend on current behaviour, or where competitive moats outweigh technical debt burden.

Your bug backlog will never be empty. That’s normal. What matters is systematic strategic technical debt management using frameworks that quantify costs, measure impact, and defend decisions with business language stakeholders understand.

Use the severity classification matrix. Calculate ROI using the formula provided. Prioritise the 20% of bugs causing 80% of impact. Document workarounds for strategic non-fixes. And allocate saved engineering hours to features that drive revenue instead of chasing technical perfection that no customer asked for.

The counterintuitive truth about hidden economics in technical decisions: sometimes the most valuable engineering work is the bug you deliberately choose not to fix.

FAQ

Should I Fix Every Bug in My Software Product?

No. You need systematic bug triage that evaluates fix cost against impact cost. Use severity classification and ROI analysis to determine which bugs warrant immediate attention versus strategic deferral or permanent non-fix status based on business value rather than technical perfectionism.

When Is It Okay to Leave a Bug Unfixed in Production?

When fix cost exceeds impact cost over the bug’s expected lifespan. When fixing would break customer workflows via backward compatibility issues. When bugs create competitive moats. Or when engineering resources deliver higher ROI through feature development rather than bug remediation.

How Do I Know If a Bug Fix Will Cost More Than the Bug Itself?

Calculate total fix cost – development, testing, deployment, regression risk – and compare against annual impact cost (support tickets, user friction, workaround maintenance) multiplied by expected years until product retirement. If fix cost exceeds 3-year impact cost, consider leaving unfixed.

Can Leaving Some Bugs Unfixed Actually Help My Business?

Yes, in specific scenarios. Bugs that customers have built workflows around create switching costs. Bugs that competitors cannot replicate create competitive moats. And intentional limitations in freemium models drive premium upgrades when positioned correctly.

What’s the Difference Between a Bug and a Feature When Customers Rely on It?

When customers build workflows, integrations, or processes that depend on specific software behaviour – even if technically incorrect – fixing the “bug” becomes a breaking change. At this point, the bug has functional feature status requiring backward compatibility consideration.

How to Implement a Bug Severity Classification System for My Team?

Create a matrix with two dimensions: impact (P0/P1/P2/P3) and fix cost (High/Medium/Low). Define specific criteria for each category. Document triage decision rules. Train your team on consistent application. Use the matrix in sprint planning to allocate resources systematically.

Bug Fix vs Workaround: Which Is More Cost-Effective?

Compare fix cost against perpetual workaround maintenance cost. If fix cost exceeds 2-3 years of workaround support effort, document the workaround formally, train your support team, and defer the fix. Consider workaround sustainability and customer satisfaction in your long-term calculation.

Fix Now vs Fix Later: When Does Technical Debt Compound vs Stabilise?

Technical debt compounds when bugs interfere with future development or accumulate integration dependencies. Debt stabilises when bugs exist in isolated legacy code paths with no planned enhancements. Use roadmap analysis to identify compounding bugs requiring earlier remediation.

How to Create a Cost-Benefit Analysis Template for Bug Fixes?

Include these variables: development hours, QA cycles, deployment risk, annual support tickets, resolution time, opportunity cost. Calculate fix cost total and annual impact cost. Compute ROI using (Impact – Fix) / Fix formula. Add a 3-year projection row for time horizon analysis.

What Happens When Customers Build Workarounds That Depend on Buggy Behaviour?

Customers develop institutional knowledge, scripts, integrations, and processes assuming the bug exists. Fixing creates a breaking change requiring customer code updates, retraining, and potential data migration. Assess customer dependency via usage analytics before remediation.

How Can Bugs Create Competitive Advantages or Technical Moats?

Proprietary buggy behaviour that customers integrate with creates switching costs. Competitors cannot replicate exact bug patterns without reverse engineering. Documented workarounds become customer institutional knowledge, increasing migration friction. Strategic bugs create accidental lock-in.

Why Would Fixing a Bug Break Backward Compatibility With Customer Workflows?

Customers adapt processes to current behaviour regardless of technical correctness. API integrations depend on specific response patterns. Data imports rely on validation quirks. Fixing changes these established patterns, requiring customers to modify integrations, scripts, and workflows simultaneously.

AUTHOR

James A. Wondrasek James A. Wondrasek

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