Edge Cache Layer

A serverless edge caching solution that runs on 300+ POPs worldwide. Reduces latency by 70% on average and absorbs traffic spikes at the edge.

Why I built it

A client was paying $40k/month for a commercial CDN that could not cache their dynamic content. I built them a small edge worker that cached the cacheable parts and let the rest pass through. Cost dropped to $800/month. Latency dropped by 70%. They asked me to open-source it.

Features

• Runs on Cloudflare Workers, Vercel Edge, and Deno Deploy
• Stale-while-revalidate with configurable TTLs
• Tag-based invalidation — invalidate by content tag, not by URL
• Per-region analytics — see hit rates by region
• Zero-config cache key — sensible defaults, override when needed

What I learned

Caching is a correctness problem disguised as a performance problem. The hard part is not storing bytes at the edge — it is invalidating the right bytes at the right time. Tag-based invalidation was the unlock.