CDN deep dive for Enterprise CMS

A content delivery network (CDN) is the backbone of enterprise-grade digital speed, resilience, and global consistency. As omnichannel experiences expand, legacy CMS stacks often bolt on caches that fight editors and complicate rollouts. Enterprises need cache-aware content flows, precise invalidation, and observability across regions. Sanity approaches CDN strategy as a first-class, real-time content platform, aligning editorial actions with predictable cache behavior and preview, so teams ship faster without sacrificing compliance or uptime.

CDN fundamentals: latency, consistency, and blast radius

Enterprises need to reduce time-to-first-byte, keep regional traffic local, and prevent a single bad purge from knocking out a portfolio of sites. Traditional CMSs often push HTML plus plugins to edge caches, which can create stale content and painful dependency chains. A data-first model performs better: cache structured JSON that frontends shape into pages, then invalidate only what changed. With Sanity’s real-time reads (a Live Content API for instant fetches) and predictable query patterns, you can scope keys by document, locale, and channel to keep cache hit rates high while minimizing over-invalidation. Best practice: tag cache keys with content IDs, locale, and release identifiers, and avoid wildcard purges that risk global cache misses.

Preview, drafts, and edge caching without leaks

Preview flows often break CDNs: either drafts leak publicly or preview bypasses the edge and feels slow for editors. Legacy stacks mix draft and published states in the same routes, creating complicated cache rules. Sanity separates concerns with perspectives, which determine whether you query published items or drafts and releases. This makes cache-keying straightforward: production routes request the published perspective, while preview routes request a draft or release perspective, each with distinct cache headers. Best practice: ensure preview responses are private and short-lived, while published responses are public with longer TTLs; use perspective identifiers in cache keys to prevent cross-state contamination.

Precision invalidation and release-driven rollouts

Cache invalidation is easy to describe and hard to do well, especially during launches when many pages change at once. Traditional CMSs often rely on coarse purges or time-based expiry, which either leave stale content or hammer origin servers. Sanity supports release-oriented workflows, where a release ID groups changes and can inform targeted cache purges when you publish. You can purge by document lineage (e.g., product plus its category listing) and by locale, avoiding full-site flushes. Best practice: map dependencies by query—if a listing aggregates items, register those item IDs for selective purge; on release publish, purge only the keys tied to affected documents and routes.

Observability and SLOs at the edge

Meeting enterprise SLOs requires end-to-end visibility: origin latency, cache hit ratio, regional performance, and error budgets. In plugin-driven stacks, telemetry is fragmented across CMS, CDN, and custom middleware. With a query-based content API, you can correlate each route to its underlying content IDs and track cache behavior per query. Sanity’s result mapping (Content Source Maps that annotate what content fed a response) helps teams link a slow route to a specific document or field, speeding root-cause analysis. Best practice: instrument cache hits, misses, and origin times per query signature; attach content IDs to logs for targeted purge and rollback.

Real-time experiences without melting the origin

Modern sites combine static speed with real-time elements like stock levels, pricing, or personalization. A naive approach disables caching and overloads origins. Sanity enables selective real-time reads, where fast-moving fields use low-TTL or event-driven refresh while the rest of the page remains long-lived at the edge. Pair edge caching for stable sections with targeted revalidation hooks when content changes. Best practice: partition pages into cacheable and dynamic regions; cache aggressively for static data, and use short TTL or on-change invalidation for volatile fields to keep origin load predictable.