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performance-testing-specialist

Measure frontend and backend performance bottlenecks with Lighthouse, k6, and memory profiling.

Updated Aug 27, 2026
Search Tags:#profiling#lighthouse#load-testing#performance-testing#k6#web-vitals#bundle-size
One-click install
npx skills add https://github.com/Whaleylaw/llm-lawyer --skill performance-testing-specialist
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: performance-testing-specialist
Source: https://github.com/Whaleylaw/llm-lawyer/tree/main/.claude/skills/performance-testing-specialist
Command: npx skills add https://github.com/Whaleylaw/llm-lawyer --skill performance-testing-specialist

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill helps teams measure, diagnose, and remediate web application performance issues to improve user experience and reliability by providing focused guidance and tests for page load, runtime behavior, and server response characteristics.

Core Features & Use Cases

  • Core Web Vitals & Lighthouse Audits: Procedures and thresholds for LCP, FID, CLS, and Lighthouse performance scoring to validate production builds.
  • Load & API Testing: Guidance for k6 and artillery-based load tests to measure p95/p99 latencies and error rates under realistic concurrency.
  • Runtime Profiling & Memory Analysis: Steps for identifying long tasks, heap growth, and memory leaks using browser APIs and DevTools profiling.
  • Bundle & Asset Budgeting: Recommendations and checks for JS/CSS bundle sizes and image optimization to enforce size budgets before release.
  • Use Case: Validate a production build before release by running Lighthouse, executing k6 load scenarios for critical endpoints, and profiling the app for long tasks and memory regressions.

Quick Start

Run a Lighthouse audit and a k6 load test against the local production build at http://localhost:3000 and report Core Web Vitals, bundle sizes, and p95 API latencies.

Frequently Asked Questions about performance-testing-specialist

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I identify frontend and backend web performance bottlenecks in my application?▼

To identify web performance bottlenecks, run Lighthouse audits for Core Web Vitals metrics like LCP and CLS, execute k6 load tests to measure API endpoint p95 latencies, and profile long tasks and heap growth to isolate frontend and backend regressions.

What's the best way to set up load testing for API endpoints with configurable SLA thresholds?▼

Setting up load testing with configurable SLAs involves using k6 or artillery to execute concurrency scenarios against API endpoints, measuring p95 and p99 latencies and error rates to validate backend performance under realistic traffic conditions.

How does memory profiling help find long tasks and heap growth in single-page applications?▼

Memory profiling identifies long tasks and heap growth in single-page applications by leveraging browser APIs and DevTools to monitor runtime behavior, catching memory leaks and long tasks that degrade runtime performance and user experience.

Can I enforce JS and CSS bundle size budgets before a production release?▼

Yes, you can enforce bundle size budgets by running pre-release asset checks that validate JS and CSS bundle sizes and image optimization, ensuring production builds meet strict payload size limits before deployment.

Does this performance testing approach work for validating a local production build at localhost?▼

Yes, this performance testing approach works for local production builds by executing Lighthouse audits and k6 load scenarios against localhost endpoints to report Core Web Vitals, bundle sizes, and p95 API latencies.

Why should I use k6 and artillery instead of other load testing tools for CI/CD performance gates?▼

Using k6 and artillery for CI/CD performance gates enables automated execution of load scenarios with configurable SLA thresholds like p95 latency and error rates, validating endpoint reliability before deployment within continuous integration pipelines.

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