"When I joined Amazon in 1998, the company had a single U.S.-based website selling only books and running a monolithic C application on five servers, a handful of Berkeley DBs for key/value data, and a relational database. That database was called "ACB" which stood for "Amazon.Com Books," a name that failed to reflect the range of our ambition"

https://m-cacm.acm.org/magazines/2021/3/250706-a-second-conversation-with-werner-vogels/fulltext