KV Cache Optimization: Why Server-Side Prompt Caching Is the New S3 of AI Infrastructure
May 18, 2026
In the early years of cloud computing, the insight that transformed infrastructure economics was simple: storing data once and serving it many times from a distributed object store was orders of magnitude cheaper than recomputing or re-fetching it on every request. S3 became the canonical implementation of that insight. In 2026, the equivalent insight in AI inference is server-side KV cache management — and the organisations that have operationalised it are reporting 60–90% reductions in input token costs for workloads with stable, repeating context. This is not a niche optimisation. For any production AI system with a consistent system prompt, a shared knowledge base, or a high-volume API, prompt caching is the highest-ROI infrastructure investment available in the current AI cost landscape.
