Codebase Reverse System Description

Reconstruct, from an existing codebase, a technology-agnostic descriptive document of the implemented system: observed behavior, business rules, permissions, hierarchies, and external integrations relevant to product operation.

Central principle

Code is evidence of behavior. The goal is to answer what the system does and why, not how it was built. Avoid programming languages, frameworks, libraries, databases, architecture patterns (MVC, microservices, etc.), and class/function names as the axis of explanation.

Golden rule for every sentence: "If I rewrote this system from scratch on another stack, would this sentence still be true?" If not, rewrite it in business terms.

Permitted exceptions (only when essential to understand the current domain):

• External integration/provider names (ERPs, gateways, BI, identity, analytics).
• Access roles/profiles and organizational hierarchy levels.
• Entity attribute names when needed to preserve business semantics (not to detail technical structure).

When to use