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