[poooogles]

Bit of both, no point moving it as the automation/clients that dump data to S3 make it quite hard to change.

[boulos]

GCS supports the S3 API modulo resumable uploads (we do them differently): https://cloud.google.com/storage/docs/migrating

Feel free to send me a note, my contact info is in my profile (I helped build preemptible VMs and I'm sort of fascinated you're doing this).