Principal engineering

Overview

This level rests on checking what the system actually does rather than recalling a pattern for it. Ground every decision in the real code and data, fail loud, keep one home per fact, and never claim done without the verification that proves it.

Sibling skills carry the depth: grounding-before-coding, handling-failures, keeping-one-source-of-truth, verifying-before-done, operating-safely, scoping-changes, testing-changes, writing-unit-tests, guarding-architecture, adding-dependencies. Load the matching one on top of this.

When to invoke