Terravek accumulated archives the way most companies of our age did: by accident, one office at a time. By the end of 2020 we had 2.4 PB of imagery and derived products spread across four regional stores with three different access patterns and two different metadata conventions.
We consolidated it into a single object store in eu-nl-1 over eleven weeks. The goal was zero customer-visible disruption and we hit it — not a single ticket referencing the migration.
The technique was not clever. We built a metadata index first, ran it read-only alongside the existing systems for three weeks until it agreed with all four of them, and only then started moving bytes. Every object was verified by checksum on arrival and the source was kept for 90 days.
The genuinely hard part was the two metadata conventions. Reconciling them required decisions about what a delivery 'is' that nobody had ever had to write down, because within one office everyone already agreed. Those conversations took longer than the data transfer.
Lesson: a migration is a schema problem wearing a bandwidth problem's clothes.