vtex-io-application-performance

SKILL.md

VTEX IO application performance

When this skill applies

Use this skill when you optimize VTEX IO backends (typically Node with @vtex/api / Koa-style middleware, or .NET services) for performance and resilience: caching, deduplicating work, parallel I/O, and efficient configuration loading—not only “add a cache.”

Adding an in-memory LRU (per pod) for hot keys

Adding VBase persistence for shared cache across pods, optionally with stale-while-revalidate (return stale, refresh in background)

Loading AppSettings (or similar) once at startup or on a TTL refresh vs every request

Parallelizing independent client calls (Promise.all) instead of serial waterfalls

Passing ctx.clients (e.g. vbase) into client helpers or resolvers so caches are testable and explicit

Do not use this skill for:

Choosing /_v/private vs public paths or Cache-Control at the edge → vtex-io-service-paths-and-cdn

GraphQL @cacheControl field semantics only → vtex-io-graphql-api

Decision rules