There’s a pattern I see in almost every enterprise engagement. The AI strategy is sound, the use cases are well-defined, leadership is aligned. And then we look at the data architecture, and the whole thing unravels.

The AI isn’t the problem. The architecture underneath it is.

The compounding cost nobody budgets for

Technical debt is a familiar concept in software engineering, but it behaves differently in data and AI systems. In most real-world ML systems, the actual model code is a tiny fraction of the whole. The vast majority is surrounding infrastructure: data pipelines, configuration management, monitoring. And all of that infrastructure sits on top of your existing data architecture, inheriting every shortcut and compromise made over the past decade.

McKinsey’s research into enterprise technology estates found that technical debt accounts for roughly 40 percent of IT balance sheets, and that companies pay an additional 10 to 20 percent on top of every project just to work around existing debt. Their survey of CIOs found that 30 percent believed more than a fifth of their budget for new products was being quietly diverted to resolving legacy issues.

For AI initiatives, the picture is considerably worse. The RAND Corporation’s 2024 study, based on interviews with 65 experienced data scientists and engineers, found that over 80 percent of AI projects fail. That’s twice the failure rate of non-AI technology projects. When you see a gap that wide, it tells you something about the specific demands AI places on existing infrastructure. MIT’s NANDA Lab confirmed this in August 2025 with granular data: 95 percent of generative AI pilots fail to deliver measurable profit-and-loss impact. Internal builds succeed roughly a third of the time compared to two-thirds for specialised vendors, a gap driven largely by data infrastructure maturity.

Why AI exposes architecture debt faster than anything else

Traditional analytics can tolerate a surprising amount of architectural compromise. Reports can be patched together from fragmented sources. Dashboards can work around inconsistent data models. Business intelligence, for all its value, is relatively forgiving.

AI demands far more from your data estate. Machine learning models are acutely sensitive to the quality, consistency, and accessibility of the data they consume. A data warehouse that produces acceptable weekly reports can be wholly inadequate for training a model or powering a real-time inference pipeline. The gaps that were manageable nuisances for BI become fatal flaws when you try to build AI on top of them.

The Informatica CDO Insights 2025 survey put numbers to this: the top obstacles to AI success were data quality and readiness at 43 percent, lack of technical maturity at 43 percent, and shortage of skills at 35 percent. Two of those three are direct consequences of accumulated architecture debt. Gartner’s own research found that 63 percent of organisations either don’t have or aren’t sure they have the right data management practices for AI. That should alarm any CTO relying on existing infrastructure to power new AI workloads.

And it shows in the abandonment numbers. S&P Global Market Intelligence’s 2025 survey of over 1,000 enterprises across North America and Europe found that 42 percent of companies abandoned most of their AI initiatives, up from 17 percent just a year earlier. The average organisation scrapped 46 percent of their AI proofs of concept before reaching production.

The pace is picking up. McKinsey’s November 2025 State of AI report found that while 88 percent of companies now use AI in some form, only 39 percent report any measurable impact on earnings. A mere 6 percent qualify as “high performers” generating more than 5 percent of EBIT from AI. Two-thirds of organisations haven’t even begun scaling AI enterprise-wide. Gartner’s June 2025 forecast went further: more than 40 percent of agentic AI projects will be cancelled by the end of 2027 due to escalating costs, unclear business value, and inadequate risk controls. Separately, they estimate that 60 percent of AI projects will be abandoned through 2026 because organisations lack AI-ready data.

The five types of architecture debt that kill AI projects

In my experience across enterprise data environments, architecture debt tends to cluster into five distinct categories. Each one compounds the others, and most organisations are dealing with at least three simultaneously.

1. Data silo debt

This is the most visible form. Data lives in disconnected systems with no unified access layer. Each department has its own databases, its own definitions, its own extract processes. When an AI initiative needs customer data joined with operational data joined with financial data, the integration work alone can consume months.

The root cause is usually years of organic growth. Each new system was implemented to solve a specific problem, with no overarching data architecture. The result is what McKinsey has described as “digital dark matter”: data assets that exist but are effectively invisible to the organisation.

2. Schema and semantic debt

Even when data is technically accessible, it often lacks consistent definitions. “Customer” means something different in the CRM than it does in the billing system. “Revenue” is calculated differently across divisions. Date formats vary. Currency handling is inconsistent.

This kind of debt is particularly dangerous for AI because models will happily train on semantically inconsistent data and produce results that look plausible but are fundamentally flawed. The errors don’t surface immediately. They compound over time as the model makes decisions based on misaligned definitions.

3. Pipeline fragility debt

Legacy ETL processes are often built as brittle, point-to-point integrations. They work until they don’t. A schema change in a source system breaks a downstream pipeline. A batch job fails silently over a weekend and nobody notices until Monday. Data arrives late, arrives duplicated, or doesn’t arrive at all.

For AI workloads that depend on fresh, reliable data, pipeline fragility is an existential risk. A model making real-time decisions on stale data can cause more damage than no model at all.

4. Governance and lineage debt

Many organisations lack basic data lineage: the ability to trace a data point from its source through every transformation to its final consumption point. Without lineage, you cannot audit model inputs. You cannot demonstrate compliance. You cannot debug unexpected model behaviour.

This debt tends to accumulate quietly because governance infrastructure doesn’t directly produce revenue. It gets deferred in favour of more visible projects, right up until a regulatory inquiry or a model failure makes it urgent.

5. Infrastructure scaling debt

Architecture decisions made for batch workloads at moderate scale often cannot support the computational demands of AI. Training jobs need different compute profiles than serving inference. Real-time streaming has different infrastructure requirements than daily batch processing. When the underlying platform wasn’t designed with these workloads in mind, organisations face expensive re-platforming or painful workarounds.

Architecture debt diagnostic

Explore each debt type to check for warning signs in your environment. Rate your exposure to get a quick read on where architecture debt may be undermining your AI initiatives.

The architecture review that changes the trajectory

Architecture debt is invisible from the boardroom. Leadership sees the AI strategy. They see the use cases. They see the vendor demos. What they don’t see is the technical foundation that will determine whether any of it actually works at production scale.

This is why we start every engagement with a thorough architecture review. Before writing a single line of code or deploying a single model, we need to understand the current state of the data estate. What systems exist? How do they connect? Where are the gaps in quality, lineage, and governance? What can be remediated, and what needs to be replaced?

It isn’t glamorous work. But it’s the work that determines whether an AI initiative delivers value in year one or joins the majority that fail to generate measurable returns.

What AI-ready architecture actually looks like

Based on what we’ve seen work in enterprise environments, AI-ready architecture shares several common characteristics.

Unified data layer. A single platform that provides consistent access to data across the organisation, eliminating point-to-point integrations. Microsoft Fabric’s lakehouse architecture is specifically designed for this, bringing together data engineering, data science, real-time analytics, and business intelligence on a shared foundation with OneLake as the single data store.

Semantic consistency. A governed semantic model that ensures “customer,” “revenue,” and other key business concepts mean the same thing regardless of where or how they’re consumed. Getting this right is the difference between a model you can trust and one you can’t.

Observable, resilient pipelines. Data pipelines with built-in monitoring, alerting, and recovery. When something fails (and it will), the system detects it immediately and either self-heals or escalates. No more silent failures that corrupt downstream models for days before anyone notices.

Lineage and governance by design. Data cataloguing, lineage tracking, and access controls built into the platform from day one, not bolted on after the fact. Microsoft Purview integration with Fabric provides this natively, but only if the architecture is designed to take advantage of it.

Elastic compute. The ability to scale compute independently of storage, matching resources to workload requirements. Training a model shouldn’t compete for resources with serving dashboards, and neither should bottleneck on infrastructure that was sized for last year’s data volumes.

The real cost of deferring

Every month of deferred architecture remediation increases the cost of eventual resolution. McKinsey’s analysis of 220 companies found a significant correlation between technical debt scores and business performance: companies in the bottom 20 percent for technical debt management were 40 percent more likely to cancel or fail to complete modernisation efforts. Meanwhile, those with the lowest debt ratios experienced 20 percent higher revenue growth.

The organisations that succeed with AI aren’t the ones with the best models or the most sophisticated algorithms. They’re the ones that invested in the foundations first.

Design the architecture. Then build on it. Then manage it continuously.

That’s the order that works.


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Sources

  1. McKinsey & Company. “Tech Debt: Reclaiming Tech Equity.” October 2020.
  2. McKinsey & Company. “Breaking Technical Debt’s Vicious Cycle to Modernize Your Business.” April 2023.
  3. McKinsey & Company. “Demystifying Digital Dark Matter: A New Standard to Tame Technical Debt.” June 2022.
  4. McKinsey & Company. “The State of AI: How Organizations Are Rewiring to Capture Value.” November 2025.
  5. Ryseff, J., De Bruhl, B., & Newberry, S. “The Root Causes of Failure for Artificial Intelligence Projects and How They Can Succeed.” RAND Corporation, RR-A2680-1, 2024.
  6. S&P Global Market Intelligence. “Voice of the Enterprise: AI & Machine Learning, Use Cases 2025.” March 2025.
  7. Gartner. “Gartner Predicts Over 40% of Agentic AI Projects Will Be Canceled by End of 2027.” June 2025.
  8. Gartner. “60% of AI Projects Will Be Abandoned Through 2026 Due to Lack of AI-Ready Data.” February 2025.
  9. MIT NANDA Lab. “The GenAI Divide: How Enterprises Succeed or Fail with Generative AI.” August 2025.
  10. Informatica. “CDO Insights 2025 Survey.” 2025.