Three multi-region topologies that work and one that mostly does not, what an Iceberg commit costs across regions, and where the catalog has to live.
Credential vending end to end: the wire protocol, scoped access on each cloud, remote signing, credential lifetime on long jobs, and failures that look like bugs.
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.
