# Engineering record

[Documentation](../README.md) · [Standards](standards.md) · [Development workflow](../guides/development.md)

The [plans](plans) and [specifications](specs) retain dated implementation intent, tradeoffs and acceptance criteria. These records help trace why a subsystem exists. They are not a feature catalog, release certification or current deployment instructions.

Use the [changelog](../../CHANGELOG.md), current architecture and exact evaluated source revision to determine what shipped. Historical plans can refer to earlier paths, configuration, model policies and sample counts. Current [data acceptance](../research/data-quality.md) and [operations](../operations/deployment.md) take precedence.