You spend weeks tuning an AI chatbot. Answers are accurate. Stakeholders sign off, and you ship it. Three months later, the system is confidently wrong about a third of what users ask. Nobody changed the model, and nobody touched the prompts. The world moved, pricing changed, a policy updated, a product spec shipped a new version, and the underlying knowledge store didn’t move with it.
This is not a hypothetical. It’s one of the most common production failure modes in enterprise AI right now, and most data engineering teams don’t have the right tooling to catch it, regardless of how the AI system retrieves the data.
The failure that doesn’t look like a failure
An AI application doesn’t care whether it’s retrieving from a vector store, a document index, or an API call. Whatever the mechanism, nothing in a standard retrieval pipeline checks whether what it’s serving is still correct. A stale pricing document retrieves just as confidently as a current one, because the system is scoring relevance or availability, not correctness. A record with a silently missing field passes through just as cleanly as a complete one, for the same reason.
So the failure is invisible by design. Outdated or incomplete data still scores high on relevance, or passes every check a data pipeline was built to run. The model answers with full confidence because the retrieved context looks authoritative. Every dashboard you’re watching stays green. The system looks like it’s working. It’s just wrong.
I’ve watched a similar version of this happen outside the AI context, in a fintech pipeline. An upstream system changed a field without notifying downstream users. The pipeline did not fail; it simply propagated bad values into dashboards because the system only checked whether the job completed, not whether the data was still correct. The issue surfaced only when a customer noticed something inconsistent. By then, the bad data had already moved downstream.
Whether it’s a document that’s gone stale or a field that’s gone silently missing, the failure shape is the same: the absence of an error is not the presence of correctness, and without building proper validation layers, nothing in the pipeline could identify the problem.
Why this is a data engineering problem
Teams that hit this failure tend to misdiagnose it, and they tend to do it twice.
Blaming the model: The first instinct is to blame the model, try a different LLM, adjust the prompt. The real problem lies further upstream, at the data engineering layer, the same instinct behind the fintech failure above: monitoring built for the pipeline, not the data.
Blaming the retrieval layer: Once the model’s ruled out, the next instinct is to blame the retrieval or context layer instead and buy a better one. The timing isn’t a coincidence: as enterprises push these systems into the real production world, this gap is exactly what’s starting to surface, and the vendor response has been everywhere.
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AWS just entered the “context layer” race with a knowledge graph that learns from agent usage.
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Snowflake’s new Horizon Context and Cortex Sense target the exact symptom this piece opened with: agents giving confident wrong answers because nothing governs the business logic underneath them.
Both are real responses to a real problem, but they sit one layer above it; a knowledge graph still depends on whatever feeds it.
The real problem lies further upstream, at the data engineering layer. Teams check whether a job ran, not whether the data it moved is still true, an instinct that predates AI by years. Monitoring is built for the pipeline, not for the data.
What’s actually missing: Data observability
Data observability is a well-known concept that doesn’t get enough attention in how it’s actually implemented. The relevant metric isn’t a percentage — it’s coverage: what fraction of critical datasets have lineage that’s actually queryable, versus only living in someone’s head.
Uber built a dedicated data quality and observability platform long before retrieval-augmented generation existed. Their Unified Data Quality platform supports more than 2,000 critical datasets and detects around 90% of data quality incidents before they reach downstream consumers.
Netflix solved a different piece of the same problem, building a company-wide data lineage system so anyone could answer where a dataset came from and what touched it along the way. It maps dependencies across Kafka topics, ML models, and experimentation, not just warehouse tables. Similar to Uber, the platform was built for humans and now it has become more important with the rise in AI/LLM applications.
Between them, Uber and Netflix cover two of the four things worth building for. In practice, I think about it as four dimensions, each measurable on its own terms.
Correctness: Does each record conform to the shape and rules it’s supposed to, right field types, no unexpected nulls, values in range. Tools like Great Expectations and Soda handle this well: automated row and column-level validation instead of manual checks after something breaks. Track percentage of records passing validation per run.
Freshness: Is the data still current relative to its source, not just current as of its last check. Track time since last successful update per source, with an SLA per dataset rather than one blanket threshold, since some sources need hourly refresh and others don’t.
Consistency: Does the same fact read the same way everywhere it’s stored or indexed. This fails silently, it only shows up when two systems fed by the same source start disagreeing. A periodic cross-check between downstream destinations, flagging mismatch rate above a threshold, is enough to catch it early.
Lineage: Can you trace any output back to its source and every transform it passed through, the same question Netflix built its system to answer.
None of this requires infrastructure most data teams don’t already have. I know because I’ve built it, not just argued for it.
At Socure, client data arrived in whatever shape the client felt like sending it, and occasionally, quietly wrong. The challenge was building a system where incorrect data could be identified before it propagated downstream. The same principles applied: Validate what arrived, understand where it came from, and prevent bad data from becoming someone else’s problem.
Great Expectations became part of that foundation: schema and range validation at ingestion, per-source SLAs for freshness, cross-system checks for consistency, and file-level lineage. All of it sat behind a write-audit-publish pattern, where data landed in staging, was validated, and only moved downstream if it passed the required checks.
The result showed up downstream: better accuracy across the board, in reporting, in the ML models, and in AI retrieval built on top of that same data.
What to do Monday morning
If you’re running retrieval-based AI systems in production, the diagnostic question isn’t which model to try next or which retrieval architecture to migrate to. It’s four narrower questions:
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Is the underlying data validated against the standards required by its consumers?
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What’s the oldest piece of content currently being served with high confidence?
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Would two chunks of the same source ever disagree with each other in the same retrieval result?
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Could you trace where it came from if it turned out to be wrong?
If you can’t answer those questions, then the gap lies in the pipeline between your source systems and whatever your agent reads from. That’s a data engineering fix, not a model swap or a vendor migration.
Whether you’re building reporting pipelines, ML systems, or AI agents, correctness, freshness, consistency, and lineage are what make data trustworthy. AI simply exposes weaknesses that have existed in data engineering all along.
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