Can verify. When I started in the catalog department in '97, "the catalog" was essentially a giant Berkeley DB keyed on ISBN/ASIN that was built/updated and pushed out (via a mountain of Perl tools) to every web server in the fleet on a regular cadence. There were a bunch of other DBs too, like for indexes, product reviews, and other site features. Once the files landed, the deploy tooling would "flip the symlinks" to make them live.

Berkeley DBs were the go-to online databases for a long time at Amazon, at least until I left at the turn of the century. We had Oracle databases too, but they weren't used in production, they were just another source of truth for the BDBs.