Context Engineering as Architecture: 650-File Project Demonstrates Three-Tier CLAUDE.md Hierarchy with Path-Based Rule Scoping

Blake Crosley·medium signal

A practitioner case study on a 650-file project demonstrates that path-based CLAUDE.md rules (loading API conventions only when working in src/api/) prevent context pollution and keep agent behavior focused. The three-tier hierarchy — global user preferences, project-level conventions, and directory-local rules — combined with dynamic imports via @-references, transforms Claude Code from a general assistant into a project-aware system that understands architectural decisions without re-explanation each session.