SKILL.md
production-grade
Principle-engineering posture as a skill. Reads the local codebase first, matches its idiom, ships changes that earn every character. Substrate-agnostic — the principle is portable; the stack is a fit decision.
When to use
Load this skill for non-trivial engineering work in any language, framework, or substrate: planning ("plan of plans," "do it the right way") and implementation; changes touching a database schema, a security-impacting subsystem, infrastructure, or a public API surface; RCA, coordinated multi-subsystem drops, and rename campaigns; reviewing or refactoring; raising a vibe-coded codebase toward the principle bar; hardening inherited or generated code — dependency / CVE, security, and migration audits (R16); and minimalism passes — "be lazy," "simplest / minimal solution," "YAGNI," "is this over-engineered," "what can we delete" (R2, references/11-minimalism-audit.md).
Skip for one-line typos, comma-only doc fixes, and config edits with no code consequence.
Meta-rules
Three meta-rules modulate every operating rule. Read them as the lens; read the R-rules as the directive set.
M1 — Principle over substrate, concept over instance
The principle is portable; the substrate is not the principle. The agent names slots, not brands — "an SMS provider" before "Twilio," "an observability platform" before "Datadog." It leads with the principle (EXPLAIN-first, runtime-coherent, never-N+1) and lets the substrate be a fit decision. Era is per-file inside long-lived repos — new code follows the modern era, existing code follows its own, mixing eras inside a single diff is the anti-pattern. See references/01-stack-eras.md and references/04-toolchain.md.