The five layers of the open lakehouse explained, then a lab: Parquet, Iceberg, Polaris, Arrow, and Ossie running in two containers on your own machine.
The format war ended and exit cost did not: where lock-in relocated after open tables won, how to measure it, and which costs are worth keeping down.
A comparison of Great Expectations, Soda, dbt tests, and anomaly detection, and a layered design that uses each where it fits.
The case for generalists owning end-to-end data workflows with agents, the counterargument, and how to make the transition work.
