FDE Field Notes
Insights from our work with customers. Explore the patterns, diagnostics, and recommendations Vercel’s Forward Deployed Engineers use in production.
Professional guides
Optimize CSS output after moving Next.js from webpack to Turbopack
Diagnose larger CSS after moving Next.js to Turbopack. Use the agent skill to compare route-level output, identify causes, and test targeted fixes.
Sitemap lastmod should track content, not deployments
Set accurate sitemap lastmod dates in Next.js using stored content timestamps, targeted revalidation, and checks that distinguish content changes from builds.
Technical audits: Finding the bottlenecks that cost performance, money, and velocity
How Vercel's Forward Deployed Engineering team runs code review, web performance, and usage audits, the recurring patterns we fix, and the diagnostics we use to find them.
Caching audits: Five antipatterns that cost you performance and money
Five caching antipatterns from hundreds of Vercel technical audits: write amplification, deploy-wiped caches, spinner shells, and how to diagnose each.