Building and shipping team layers: anatomy, extends, priority and merging, publishing, testing, pitfalls.

The kit API, the build/runtime boundary, option channels, hooks, templates, testing and publishing.

Startup sequence, Nitro and h3, the unjs toolbelt, auto-imports, Vite transforms, rendering modes.

Why mismatches happen, the catalogue of causes, the diagnosis workflow and author responsibilities.

Three lifetimes, server and client leak patterns, heap-snapshot detection, safe patterns.

Build, server, network and client performance levers, always measured before applied.

Designing tooling APIs for a team, release discipline, security awareness, review checklists.

Nuxt 4.5, the Nuxt 5 changes, Vue 3.5 and the ecosystem to know by name.