I am curious is anyone using DuckDB in prod?

Yes, we run DuckDB + DuckLake in prod for https://www.definite.app/

Is DuckLake compatible with Iceberg? I remember they create a new catalog.

Yes, you can use

INSTALL iceberg;

to start working with iceberg https://duckdb.org/docs/stable/core_extensions/iceberg/overv...

of course, why wouldn't you?

I was using it even before it hit 1.0