Comment by Spivak

Once you start asking to query the log by keys, multi-tenancy trees of topics, synchronous commits-ish, and schemas aren't we just in normal db territory where the kafka log becomes the query log. I think you need to go backwards and be like what is the feature a rdbms/nosql db can't do and go from there. Because the wishlist is looking like CQRS with the front queue being durable but events removed once persisted in the backing db where the clients query events from the db.

The backing db in this wishlist would be something in the vein of Aurora to achieve the storage compute split.