th-engineering

name	th-engineering
description	Use for engineering-quality work on any change or codebase — holding an implementation or review to the engineering quality bar, code readability, test-suite rigor, module boundaries and dependency chains, diagnosing hard bugs and flaky failures to root cause, post-refactor cruft cleanup, codebase documentation, creating or reviewing skills against the skill quality bar, or Excalidraw diagrams. Route to exactly one subskill per subdomain; fan out subagents when a task spans several. Triggers: "hold this to the engineering bar", "is this code readable", "review these tests", "untangle these dependencies", "diagnose this", "flaky test", "clean up this refactor", "document this service", "audit the docs", "review this skill", "draw a diagram".
metadata	{"owner":"tze","authors":["tze","Claude Fable 5","OpenAI Codex"],"status":"active","last_reviewed":"2026-07-19"}
compatibility	skill-standards auditing and excalidraw rendering require uv and Python 3.11+; excalidraw-diagram additionally requires Playwright Chromium setup on first render.

TH Engineering

Superskill router for the engineering quality bar. Nine subskills live under subskills/, each a complete skill package. Not in the global catalog — discover lazily, load at most one subskill body per subdomain, prefer one subagent per subskill when a task spans several (see "Subagent dispatch").

/th-projects governs the project (doctrine, specs, topology, audits); /th-tooling governs this machine's harness (installed skills, dotfiles, snapshot state); this superskill governs the change: the bar code must clear while written, reviewed, or cleaned up.

Discover subskills

PKG="$(dirname "<absolute-path-to-this-SKILL.md>")"
find "$PKG/subskills" -maxdepth 2 -name SKILL.md
rg -n "^name:|^description:" "$PKG"/subskills/*/SKILL.md

Routing table

Task intent	Subskill	Typical trigger
Holistic quality bar: default engineering biases, definition of done; the source projects' craft-and-care pillars adopt by reference.	subskills/engineering-bar/SKILL.md	"hold this to the engineering bar", "is this change complete"
Readability and maintainability: naming, function shape, abstraction altitude, comments, simplicity over cleverness.	subskills/code-readability/SKILL.md	"is this readable", "simplify this code"
Test quality: behavior-focused assertions, edge/failure coverage, regression tests, tautology and flake elimination.	subskills/test-rigor/SKILL.md	"review these tests", "what coverage is missing"
Module boundaries and dependency chains: direction, layering, cycles, public surface, third-party policy.	subskills/dependency-hygiene/SKILL.md	"untangle these dependencies", "should we add this library"
Codebase documentation: synthesis, diagrams, contract-level code-cited facts, interface semantics cards, human-readable doc sites.	subskills/documentation/SKILL.md	"document this service", "audit docs for stale claims"
Evidence bar for diagnosing hard bugs, flaky failures, and perf regressions: feedback loop, ranked hypotheses, tagged instrumentation, regression test at the correct seam.	subskills/diagnosis/SKILL.md	"diagnose this", "fails one run in twenty", "find the regression"
Finish same-repo refactors/renames/migrations: delete lingering aliases, wrappers, fallbacks, dead flags.	subskills/cruft-cleanup/SKILL.md	"clean up this refactor", "old path still works"
Skill/superskill quality bar: triggers, grounding, metadata, routing, context efficiency, validation.	subskills/skill-standards/SKILL.md	"review this skill", "should this be a superskill"
Excalidraw diagrams into/out of workflows, architectures, protocols, Mermaid.	subskills/excalidraw-diagram/SKILL.md	"draw a diagram", "convert this Mermaid"

Routing rules

• Bar vs. subdomain: holistic "is this good/done" → engineering-bar; an ask naming one subdomain → that subskill directly.
• Change-level vs. project-level: changes, diffs, PRs, modules → here. Repo-wide audits, specs, prioritization, knowledge architecture → /th-projects (whose craft-and-care pillar adopts engineering-bar by reference).
• Build quality vs. product feel: how the code is built → here; how the product feels to use (UX contracts, perceived latency, copy, discoverability, accessibility) → /th-design. A review that surfaces a user-facing feel finding routes it there instead of absorbing it.
• Docs craft vs. knowledge architecture: README/docs/doc-site quality → documentation (consumes excalidraw-diagram for its diagrams — an expected pairing); five-pillar shape work → /th-projects.
• Skill content vs. harness state: skill quality, authoring, review → skill-standards; whether installed skills are used, linked, fresh on this machine → /th-tooling (audit-skill-hygiene, refresh-snapshots).
• Fallback: quality-adjacent but no row fits → answer from router-level context or ask; don't load a subskill to browse.

Subagent dispatch

Subskills are independent subdomains; multi-subdomain work parallelizes:

• Quality sweep across subdomains: one subagent per relevant subskill. Each prompt carries (1) the absolute path to its subskills/<name>/SKILL.md with instruction to read and apply it, (2) exact scope (diff, files, directories), (3) the output contract: findings with file:line evidence and a proposed fix. Parent synthesizes and dedupes; conflicts resolve via engineering-bar's biases.
• Iteration-heavy single subdomains (excalidraw render loop, skill audit-and-fix): delegate the whole loop, review the returned artifact.
• One narrow question: load the single subskill, answer directly.

Shared invariants (all subskills)

• Quality claims are reviewable expectations, not taste: every finding cites file:line (or skill-path) evidence and the expectation it violates.
• engineering-bar's default biases are the baseline all subskills assume; a project's about/craft-and-care/ overrides them where present.
• Fix-it-now beats file-it-away: the current implementation/recovery owner fixes small in-scope findings. Independent reviewers retain verifier ownership; new architecture, trust-boundary, contract, or risk-class findings return to /th-projects allocation/spec gates instead of silently expanding the diff.
• Subskills reference each other by relative path (../engineering-bar/…); those paths are package-internal and stable.