Getting bytes in and out: job contexts through the presigned upload plane, the S3-compatible endpoint at storage.givemeanode.com, and large multi-part uploads. Measured every ten minutes by a full presigned round trip plus a SigV4-signed PUT/GET/DELETE at the public S3 door, and hourly by a 257 MiB two-part upload declared, uploaded, assembled, and read back through the same create_context / finalize_context calls customers make.