dRafaleDdRafaleD/cybersec-skills/skills/engineering/lean-perf/SKILL.md

lean-perf

Skill2 starsChanged 55 days agoMITView on GitHub

Runs token-efficient performance reviews for Cursor and Codex. Inventories N-plus-1 loops, SELECT star, unbounded reads, and sync I/O in request paths, then reports compact hot-path fixes. Use when the user asks for performance, slow queries, N+1, latency, or cheaper I/O. Do not dump profiles, flame graphs, or rewrite unrelated modules.

In this repository21 other files it gives its agents.
- lean-cryptoSkill
- lean-mobileSkill
- lean-privacySkill
- lean-secSkill
- lean-webSkill
- lean-a11ySkill
- lean-depsSkill
- lean-docsSkill
- lean-reviewSkill
- lean-ciSkill
- lean-cloudSkill
- lean-costSkill
- lean-hardeningSkill
- lean-iotSkill
- lean-netSkill
- lean-dfirSkill
- lean-ir-playbookSkill
- lean-malwareSkill
- lean-osintSkill
- lean-phishSkill
- lean-threat-modelSkill

The file

We split this skill into the rules it gives an agent

3 rules. About 0 are common, 1 is distinctive, and 2 are very specific to this project.

≈0
Common · estimate
Many files like this have a rule of this kind.
≈1
Distinctive · estimate
This author's own choices. Worth a look.
2
Very specific
Tied to their project's names, files or tools. Probably skip.

Common
Distinctive
Very specific

Very specific:
Run hot. Queue await-in-loop, query-in-loop, SELECT *, no pagination.
line 37
Very specific:
Do not paste flame graphs or 10k-line profiles.
line 43
Distinctive:
No drive-by micro-optimizations of cold code.
line 44

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.

Files

SKILL.md

Lean Perf

Hot-path hygiene. Scripts list likely N+1 and unbounded reads; you confirm a few loops.

Let SKILL_ROOT be the folder that contains this SKILL.md. Prefer python3; on Windows use py -3.

python3 "$SKILL_ROOT/scripts/lean_perf.py" hot .
python3 "$SKILL_ROOT/scripts/lean_perf.py" trim --chars 2500 path/to/out.txt

Mode

Default lean.

Mode	Budget
`lean`	`hot` + up to 8 slices; references/io.md; ≤6 findings
`standard`	up to 16 slices; ≤10 findings
`deep`	still no full profiler dump; ≤16 findings

Workflow

Run hot. Queue await-in-loop, query-in-loop, SELECT *, no pagination.
Slice-read. Cap quotes at 12 lines.
Report batching, indexes, pagination. Stop unless asked to patch.

Hard rules

Do not paste flame graphs or 10k-line profiles. trim if the user already has one.
No drive-by micro-optimizations of cold code.

Report template

## Lean-perf (`<mode>`)

**Hot path:** <handler> | **Budget:** files_read=<n>

| Sev | Location | Issue | Fix |
|-----|----------|-------|-----|
| HIGH | file:line | await inside map of N | Promise.all / batch query |

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