Build systems from journeys and capabilities

This applies to complete products and systems of any size: customer-facing apps, internal tools, APIs, mobile apps, and systems without a graphical interface. Build around what each user or system actor needs to accomplish, not a list of screens or a collection of CRUD endpoints. Do the product and workflow structure before implementing. Respect existing domain language, API contracts, and architecture decisions; do not silently replace them.

Before implementation: map the system

For a new system, major feature area, or cross-module workflow, first produce a concise plan covering: