Exactly-once semantics in the Iceberg sink connector: the coordinator, the control topic, offsets stored inside Iceberg snapshots, and where duplicates still get in.
Four meters, their real proportions, and how to attribute compute to a query, a table, and a team so a platform can answer what a dashboard costs to run.
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.
