If I build edge caching with Cloudflare Workers + KV, how do I do invalidation?
Don't rely on TTL alone — it's eventual and serves stale prices. Make invalidation push-based: when the price changes at origin, call Cloudflare's API to write-through to KV (or delete the key) in the same transaction/outbox. Treat KV as a cache, not the source of truth; versioned keys + a short TTL safety net.