Vercel Finds the Hidden Cost of Durable State — Week 33 Web Development

Vercel's Redis-to-DynamoDB migration exposed an N+1 control loop when a small per-query latency increase accumulated across hundreds of serialized reads. Evil Martians, Shopify, and GitButler make fairness, test stability, and model performance measurable through constrained interfaces and reproducible workloads. A long-running-agent workflow adds progressive context shaping, while Piccalilli preserves a no-JavaScript baseline—both keep changing evidence from silently breaking the system's current contract.