The SaaS marketing site stuck at 31% cache-hit

The SaaS marketing site stuck at 31% cache-hit

A B2B SaaS site had a CDN, good TTLs, and a baffling 31% cache-hit ratio. Half their traffic came from ad campaigns, and every link carried utm_source, fbclid, and gclid. To the edge, /pricing?utm_source=x and /pricing?utm_source=y were two different objects — millions of one-hit-wonder cache entries.

We told the edge to ignore tracking parameters when building cache keys, while still passing them through to analytics. The marketing query string stopped fragmenting the cache.

Cache-hit ratio climbed from 31% to 94% in 48 hours. Origin egress dropped from 410GB to 38GB that month. The pricing page, previously a cold fetch for nearly every visitor, now served from edge in single-digit milliseconds.

The number that mattered: cache-hit 31% to 94%.