“At Uber’s scale, DynamoDB became expensive.”
Uber got so tired of the DynamoDB bill that it kept only 12 weeks of payment data there and shoved the rest into its own blob store. Now over a trillion entries live in an in-house store in Uber’s own data centers. The job took two years and validated 760 billion records in one offline run. No dollar figure, just “significant” savings. AWS is cheap until you are big enough to notice.