Performance tester

Skill AtulPurohit/Antigravity-Awesome-Skills/plugins/dx-qa-automation/skills/performance-tester

Design and run performance tests to identify bottlenecks, validate SLOs, and measure system capacity. Covers load tests, stress tests, and spike tests.From its SKILL.md

Install

npx -y skills add AtulPurohit/Antigravity-Awesome-Skills --skill performance-tester

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

2 things to look at

no licenseNo license file was found in the repository. Code published without one is not open source by default, so using it at work is a question for whoever answers licensing questions where you are.
3 stars3 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

SKILL.md

2.8 KB, 634 tokens by cl100k_base, as published. Nobody here has run it

Performance Tester

Purpose

Identify performance bottlenecks and validate that systems meet SLOs under realistic and extreme load conditions.

Performance Test Types

Type	Goal	When
Load test	Validate normal traffic	Before release
Stress test	Find breaking point	Capacity planning
Spike test	Handle sudden traffic	Event preparation
Soak test	Find memory leaks	Long-running validation
Smoke test	Basic sanity check	After deploy

k6 Test Scripts

import http from 'k6/http';
import { check, sleep } from 'k6';
import { Rate, Trend } from 'k6/metrics';

const errorRate = new Rate('errors');
const apiDuration = new Trend('api_duration');

export const options = {
  scenarios: {
    // Ramping load test
    load_test: {
      executor: 'ramping-vus',
      startVUs: 0,
      stages: [
        { duration: '2m', target: 100 },   // Ramp up
        { duration: '5m', target: 100 },   // Sustain
        { duration: '2m', target: 200 },   // Increase
        { duration: '5m', target: 200 },   // Sustain
        { duration: '2m', target: 0 },     // Ramp down
      ],
    },
  },
  thresholds: {
    http_req_duration: ['p(95)<500', 'p(99)<1000'],  // SLO: P95 < 500ms
    errors: ['rate<0.01'],                             // Error rate < 1%
    http_req_failed: ['rate<0.01'],
  },
};

export default function() {
  const res = http.get('https://api.example.com/posts', {
    headers: { Authorization: `Bearer ${__ENV.API_TOKEN}` },
  });

  const success = check(res, {
    'status is 200': (r) => r.status === 200,
    'response time < 500ms': (r) => r.timings.duration < 500,
    'has data': (r) => r.json().data !== undefined,
  });

  errorRate.add(!success);
  apiDuration.add(res.timings.duration);

  sleep(1);
}

Identifying Bottlenecks

# Profile running Node.js app
node --prof app.js

# Analyze flame graph
npx clinic flame -- node server.js

# Database slow query log
SET GLOBAL slow_query_log = 1;
SET GLOBAL long_query_time = 0.1;

# Profile PostgreSQL queries
EXPLAIN (ANALYZE, BUFFERS, FORMAT JSON) SELECT ...;

Outputs

k6 test scripts for all scenarios
SLO definition (P95, P99 targets)
Performance baseline report
Bottleneck analysis
Optimization recommendations
Continuous performance monitoring setup

What ships with it

Read from the repository

Just SKILL.md. No reference files, no scripts.