Production notes
- Two identical prompts with a 10x cost gap reveal
- Token-by-token KV vector computation animation
- Stable head vs variable tail prompt breakdown
- Prefix tree build-up with cache hit and miss walkthroughs
- Cache eviction and its cost and latency impact
Prompt Caching Explained: Why Prefixes Matter
Why two identical prompts can cost 10x differently, and how KV caching and prefix trees decide which calls you pay full price for.