## Context
Node.js monorepo: switching version management to `devEngines.runtime` + `devEngines.packageManager` in package.json makes Railway report ~3x memory usage (200MB -> 700MB) for the same app.
## Verified resolution
Maintainer iloveitaly explained Railpack (via mise) did not honor `devEngines.packageManager`, so node resolution fell back to defaults while the runtime requested a different version, the mismatch caused an extra node download/extraction at startup, adding ~200MB of filesystem-cache memory. Railpack added native `devEngines` support in PR #678. The reporter's own resolution: remove a stray `.nvmrc` file that was conflicting with version resolution; after that memory stayed at the expected level.