performance_engineering

Validates system capacity through load testing, profiling, and optimization across APIs, databases, and frontends.

Updated Jan 14, 2026
One-click install
npx skills add https://github.com/jvsandhu/agentic-skills --skill performance-engineering-jvsandhu
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: performance_engineering
Source: https://github.com/jvsandhu/agentic-skills/tree/main/skills/performance_engineering
Command: npx skills add https://github.com/jvsandhu/agentic-skills --skill performance-engineering-jvsandhu

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires k6, locust, py-spy, memory_profiler, clinic, and includes references (resource) components.

What problem does it solve? Systems fail under real traffic when capacity is never validated, bottlenecks remain hidden, and performance regressions slip into production. This Skill provides structured workflows for load testing, profiling, and optimization so you can find breaking points, diagnose slow code paths, and enforce performance SLOs before users are affected. ## Core Features & Use Cases - Load, Stress, Soak, and Spike Testing: Ready-to-run k6 (JavaScript) and Locust (Python) test templates with thresholds that fail CI builds when latency or error budgets are violated. - Cross-Language Profiling: CPU, memory, and I/O profiling workflows using py-spy and memory_profiler for Python, pprof for Go, and Chrome DevTools or clinic.js for Node.js. - Optimization Playbooks: Concrete patterns for caching with Redis, eliminating N+1 database queries, cursor-based API pagination, and improving Core Web Vitals (LCP, INP, CLS). - Use Case: Before a product launch, run a k6 stress test to find the API's breaking point, profile the hottest endpoints with py-spy, add caching and query indexes, then wire the test into GitHub Actions to catch future regressions. ## Quick Start Ask the agent to write and run a k6 load test against your API endpoint with a p95 latency threshold under 500ms.

Frequently Asked Questions about performance_engineering

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

FAQPage Schema
How do I load test an API with k6?

Write a JavaScript test defining virtual user stages and thresholds, then run it with the k6 CLI. The Skill provides templates with ramp-up stages, p95 latency thresholds under 500ms, and error-rate checks below 1%.

k6 vs Locust: which load testing tool should I use?

k6 uses JavaScript, integrates with Grafana and Prometheus, and suits modern APIs and CI/CD pipelines. Locust is Python-native with a web UI, better for Python-heavy teams and complex user behavior scenarios.

How do I find memory leaks in a Python application?

Use memory_profiler with the @profile decorator to trace line-by-line memory allocation, and run soak tests to confirm leaks over time. py-spy can sample a running production process with low overhead.

Can performance tests run in CI/CD pipelines?

Yes, the Skill includes a GitHub Actions workflow that installs k6 and runs load tests on pull requests. k6 thresholds fail the build automatically when latency or error-rate budgets are violated.

Why does my load test show errors that production never sees?

The load generator machine itself may be CPU-saturated, producing false negatives. Check the injector's resource usage, mock third-party APIs like Stripe or Twilio, and use dynamic CSV data to bypass caches.

What are good latency SLOs for a user-facing API?

The Skill recommends p95 latency under 200ms and p99 under 500ms with 99.9% availability for user-facing APIs. Set targets 10-20% better than your measured baseline and iterate as the system matures.