DWHPro Insights

Insights

327 technical articles on Teradata, Snowflake, Databricks, SQL tuning and data warehouse architecture — written from production experience, not vendor decks.

Why does your test suite lie to you when the system contains an LLM

Comparison of a calculator-like deterministic system, where the same input always gives the same output, with an LLM that can give different valid outputs

A passing test means the tested assertion held for those cases, not that the whole program is correct. This limitation applies to deterministic software as well as systems containing LLMs. Traditional software tests establish behavior for tested cases, not general correctness. Deterministic programs can silently calculate wrong values. Property-based, randomized and concurrency tests can check …

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What You Actually Need to Know About LLMs Before the Next Interview

Diagram of the five transformer phases in an LLM: input tokenized, tokens embedded, N transformer blocks, output projected to vocabulary, next token predicted

“All models are wrong, but some are useful.”George Box This practical primer is part of the series on moving from data engineering into AI systems. It focuses on LLM concepts relevant to interviews and implementation; the original relative newsletter schedule is omitted. Read the related career and job-posting articles for the broader series. Publication timing …

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From Data Engineer to AI Engineer: The Real Path Popular

Three role cards: an AI strategist who defines direction, an AI developer who builds features, and an AI engineer who builds the systems that make it reliable

“The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn.”Alvin Toffler Open any job board, scroll any LinkedIn feed, sit through any earnings call, and you will run into the same wave of new titles: AI engineer, AI developer, AI strategist, machine …

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Three Rules for Choosing a Technology Career

A person at a fork between the old path toward a grey city and a sunlit route, under a signpost: choose work with consequences, specialize early, build proof not credentials

How to think about the choice when the standard path no longer reliably works. Foreword The path that worked through most of the previous decade — pick any reasonable engineering specialty, get hired into a junior role, learn the rest on the job — does not reliably work in 2026. The market has shifted. The …

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The Apprenticeship That Vanished Popular

Banks are cutting junior data engineers today. The bill comes due in 2035. Reports of technology layoffs motivate this concern, but this article does not supply a named dataset establishing the number or disproportionate junior share. The apprenticeship risk is an argument to evaluate, not an inference proven by those unsourced figures. That narrative is …

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RAG Reliability Depends on Data, Retrieval, and the Model

Illustration of a person in a suit standing beside a database cylinder

Every enterprise AI strategy deck I have seen in the past years contains the same promise: “We will build a RAG-based knowledge assistant that lets employees query our internal documents in natural language.” The board nods. The budget gets approved. Six months later, the assistant gives wrong answers, misses critical information, and nobody trusts it. …

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