Fixtures, in-memory catalogs, and golden metadata: the assertions that catch wrong rows, unsafe reruns, schema drift, and concurrent-write corruption in CI.
A repeatable test for what an Iceberg REST catalog actually serves, a scoring scheme that separates design from breakage, and the 2026 evidence across seven catalogs.
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.
