Interface Legacy Assessment

What is your
legacy
costing you?

Interface legacy rarely shows up in any budget line — but CIOs and CTOs feel it every quarter. Absorbed into dev salaries, delayed releases, and missed opportunities. This tool makes the cost visible.

Calculate my interface legacy cost → Talk to us
33%
of dev time lost to
technical debt — Stripe
40%
more maintenance costs
in high-debt orgs — McKinsey
50%
slower feature delivery
with unmanaged legacy — Gartner
Legacy signals

6 signs your enterprise has
an interface legacy problem

Legacy is everything that prevents your organisation from moving at the speed the business needs. It's a technology problem, a process problem, and a governance problem — often all three at once.

01
Technology fragmentation
Multiple stacks, disconnected systems, incompatible APIs. OutSystems next to React next to IBM. Each boundary is a maintenance cost and a coordination tax.
02
Design system entropy
Multiple style guides, inconsistent components, visual debt that compounds with every release. A rebrand becomes a multi-quarter project.
03
No governance layer
No UI architect. No ecosystem owner. Teams making independent decisions that conflict at integration. The design system exists as a slide deck, not as operational reality.
04
Tribal knowledge loss
Key people left. Documentation doesn't exist. Onboarding takes months. Every change carries hidden risk because no one fully understands the system anymore.
05
Compliance exposure
Accessibility non-compliance. Outdated licenses. APIs that can't keep up with regulatory change. Legacy that stops you meeting what the law requires.
06
Slow time-to-market
Features that should take two weeks take two months. Maintenance crowds out building. Every new initiative negotiates with accumulated debt.
Cost calculator

Find the number
hiding in your budget

Fill in what you know about your team and systems. The model translates your inputs into a conservative annual cost estimate — grounded in market benchmarks from McKinsey, Stripe, Gartner, and CISQ.

About this model These are estimates, not audits. The purpose is to make an invisible cost visible — not to replace a proper assessment. Use the number as a starting point for a conversation, not a final figure.
1
Team baselineInvestment you're already making
iCount all engineers who work on user interfaces — frontend devs, full-stack devs, and any OutSystems or low-code developers building screens.
10
All who touch the interface layer
iInclude gross salary plus employer costs: social security, benefits, equipment, licences, and office overhead. Typically 1.3–1.5× gross salary.
Include salary, benefits, overhead
iCount every app, portal, or product that has its own UI. Includes internal tools, customer portals, mobile apps, and admin dashboards.
5
That share or should share a UI layer
2
Technology fragmentationMulti-stack & disconnected systems
iEach separate frontend technology is one stack. Example: OutSystems = 1, React = 2, IBM Portal = 3. More stacks = more coordination cost.
3
OutSystems + React + IBM = 3
iHow many separate visual standards or component libraries are in use? 1 = unified. 3+ = each team builds its own buttons and patterns.
2
1 = unified, 3+ = fragmented
iWhen was the last time the frontend architecture or design system was rebuilt from scratch? Systems over 5 years old accumulate significant hidden cost.
5 yrs
5+ years is critical legacy territory
3
Governance & knowledgeOwnership, people, documentation
iIs there a single person or team responsible for frontend architecture standards, design system governance, and cross-team consistency?
iCount engineers or designers who left and took critical knowledge with them — undocumented decisions, system quirks, integration logic.
2
People carrying institutional knowledge
iHow well documented are your frontend architecture, components, and integration patterns? Missing docs multiply onboarding time and change risk.
4
Compliance exposureAccessibility, licenses, manual ops
iEU Web Accessibility Directive requires public sector and some private organisations to meet WCAG 2.1 AA. Non-compliance carries legal and reputational risk.
iOld software licences and frozen API versions create security risk and block integration with modern services. Count critical dependencies past their support date.
iAny workflow still running on spreadsheets, paper, or email instead of a digital interface. These are legacy by definition — they block scale and auditability.
5
Delivery velocity signalsHow fast and clean are your releases?
iFrom approved spec to production release. Healthy teams ship UI features in 1–2 weeks. Anything above 4 weeks signals legacy drag.
5 wks
Healthy: 1–2 weeks. Legacy signal: 4+
iWhat portion of your frontend team's time goes to keeping existing systems running vs building new value? Healthy: ~20%. Legacy warning: 50%+.
50%
Healthy: 20–30%. Legacy signal: 50%+
iCount helpdesk or support tickets caused by confusing interfaces, broken UI flows, or accessibility issues. Each ticket is a direct legacy signal.
50
Direct signal of interface failure
Estimated annual cost of interface legacy
€0
— of your frontend investment is absorbed by legacy, not building
Legacy severity index —
Lost dev productivity
—
Excess maintenance over healthy baseline
Fragmentation tax
—
Multi-stack & design system overhead
Governance & knowledge loss
—
No owner, turnover, missing docs
Compliance exposure
—
Accessibility, licenses, manual ops
Delayed time-to-market
—
Revenue drag + support cost

These are conservative estimates. The real number is almost certainly higher — because legacy cost hides in slow decisions, avoided risks, and talented people working below their potential.

I want to speak about my cost →
Benchmark sources
Productivity loss rate: Stripe Developer Report — 33% of dev time on technical debt; CodeScene 2024 — up to 42% in high-debt codebases; DEV Community 2025 — 23% as conservative baseline.  ·  Fragmentation overhead: McKinsey Digital 2024 — 40% higher maintenance costs in high-debt organisations, 25–50% slower delivery vs. competitors.  ·  Knowledge & governance cost: CISQ Cost of Poor Software Quality Report 2022 — $1.52T global impact, avg. enterprise carries $3.61M in technical debt.  ·  Compliance: Forrester Research — $100 ROI per $1 invested in UX; EU Web Accessibility Directive enforcement from 2025.  ·  Legacy maintenance: Aalpha 2025 — 60–80% of IT budget consumed by legacy systems.  ·  Time-to-market: McKinsey $2B modernisation study — 70% of initiatives blocked by legacy systems; Stripe — 2-month delay costs 25% of projected MRR.
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