engineering-principleslisted

# Engineering principles Defaults, not dogma — when a rule conflicts with the repo's established patterns, the repo wins. - **Match the repo.** Follow existing conventions, structure, and idioms even over personal preference. Consistency beats local "better". - **YAGNI.** Build only what the task needs. No speculative abstractions, config knobs, unused params, or "future-proofing". Delete dead code. - **KISS.** Simplest solution that works; optimize for the next reader, not cleverness. - **DRY with judgment.** Rule of three before abstracting; a little duplication beats the wrong abstraction; don't couple unrelated code that merely looks similar. - **Small units.** One thing, one reason to change; short functions; composition over inheritance; minimal public surface. - **Naming/comments.** Intention-revealing names; comments explain *why*, not *what*; no commented-out code; no TODO graveyards. - **Errors.** Fail fast, handle explicitly, validate at boundaries; never silently swallow. - **Minimal-scope diffs.** Smallest change that solves the problem; don't sprawl refactors into unrelated files; list unrelated improvements instead of doing them. - **Dependencies.** Prefer stdlib/existing deps; don't add a package for something trivial. - **Performance.** Clarity first; measure before optimizing. - **Tests.** Test behavior, not implementation; meaningful assertions; no coverage theater. - **Before finishing.** Re-read your diff as a reviewer; remove anything unneeded; confirm