This case study examines Protocol Zero, a proprietary "Headless" AI architectural engine designed to solve the critical "Junior Developer Problem" inherent in generic AI coding assistants. Unlike standard LLM implementations that average internet knowledge (often outdated or insecure), Protocol Zero enforces a strict, multi-tier quality hierarchy ("Platinum" to "Lead") using a GraphRAG architecture. It introduces a novel "Regressive Learning" loop that captures the delta between AI-generated code and human-committed code to auto-correct future outputs. Initially deployed for Ruby on Rails at scale, the architecture is language-agnostic and designed for high-compliance industries.