All Articles & Tutorials
Explore practical guides, step-by-step masterclasses, and foundational definitions across AI, SQL, and data systems — written in plain, human English.
All articles
What is data grain? Why you must know what one row in a table means
Grain means what one row represents. Write it down before you join or sum. Mismatched grain is why three honest queries produce three revenues.
What is a data contract?
A data contract is an explicit agreement between data producers and consumers on schema, meaning, quality, and delivery. Learn the pieces, a worked example, and when contracts beat…
How to review changes to dbt data models before they go live
Review dbt model PRs for grain, joins, filters, tests, docs, and blast radius. Green CI means the files compile. It does not mean the metric is safe for…
Leading vs lagging indicators: which business metrics warn you early
Use lagging indicators for outcomes and leading indicators for early warning. Put both on the review so a green result tile cannot hide a thin pipeline.
How to make your data analysis reproducible when you work alone
Solo analysts still need reproducibility: fixed inputs, pinned environments, clear parameters, and a re-run path so last quarter’s number can be explained without archaeology.
