Head of produck and co-founder at MotherDuck here. Happy to answer any questions!
One minor correction on the title. While we're partners with DuckDB, and they're shareholders in MotherDuck, it is MotherDuck who raised the money, not DuckDB. On the plus side, we avoid the ethical dillemma of many OSS companies associated with being open-core - DuckDB is open, MotherDuck is closed (although contributing to open).