The bill was in egress, not traffic

The bill was in egress, not traffic

A backup-storage startup in Denver had a CDN bill that grew faster than its users. Traffic was flat, but origin egress kept climbing. The cause: their origin sat in a cloud bucket that charged $0.09 per GB every time the CDN pulled from it, and a low cache-hit ratio meant constant pulls.

Two moves. First, we raised cache-hit ratio from 73% to 95% by extending TTLs on immutable assets and fixing cache keys. Second, we moved origin to a provider inside the CDN's zero-egress bandwidth alliance, dropping origin-pull cost to $0.

Origin pulls fell 81% from the cache work alone, then the remaining pulls cost nothing. The monthly bill went from $3,400 to $740.

The number that mattered: $0.09 per GB became $0.