software-engineering-eng-perf

Diagnose systems performance bottlenecks using USE and RED metrics.

Updated May 6, 2025
One-click install
npx skills add https://github.com/rodrigo-altissimo/qiartificial --skill software-engineering-eng-perf
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: software-engineering-eng-perf
Source: https://github.com/rodrigo-altissimo/qiartificial/tree/main/.claude/skills/software-engineering/eng-perf
Command: npx skills add https://github.com/rodrigo-altissimo/qiartificial --skill software-engineering-eng-perf

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Performance investigations fail when teams rely on guesses instead of measurements, leading to wasted effort and persistent latency or throughput issues.

Core Features & Use Cases

  • Systems performance diagnosis (USE Method): Evaluate utilization, saturation, and errors across CPU, memory, disk I/O, network, connections, and thread pools to determine the bottleneck.
  • Latency and service diagnosis (RED Method): Analyze Rate, Errors, and Duration using p50/p90/p95/p99 to pinpoint slow endpoints and tail-latency problems.
  • Profiling-driven root cause analysis: Use CPU profiling and flame graphs, plus memory and database investigation patterns (e.g., N+1, caching strategy, pool exhaustion) to produce actionable fixes.
  • Verification via re-measurement and load testing: Validate improvements using the same metrics and a structured load-testing protocol (smoke/load/stress/soak/spike).

Example use cases: diagnosing an API p99 latency regression, finding the CPU hotspot behind a flame graph, isolating memory leaks over time, and optimizing database queries and caching behavior.

Quick Start

Ask the AI to diagnose your performance issue by requesting the current p99 latency, the suspected endpoint or operation, the SLO target, and the relevant measurements or traces.

Frequently Asked Questions about software-engineering-eng-perf

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

FAQPage Schema
How do I diagnose p99 latency regression in an API endpoint?

Diagnose API p99 latency regression by applying the RED Method to analyze request Rate, Errors, and Duration metrics, isolating tail-latency drivers through percentile-based reasoning before proposing targeted fixes.

What is the best way to find the bottleneck causing high CPU utilization?

Find CPU bottlenecks using the USE Method to evaluate utilization, saturation, and errors, then apply evidence-based profiling and flame graph analysis to pinpoint hotspots.

How do I investigate a memory leak or exhaustion issue?

Investigate memory leaks and exhaustion by measuring utilization and saturation over time using the USE Method workflow, applying memory profiling patterns to identify the root cause.

How do I validate SLOs using load testing after a performance fix?

Validate SLOs using a structured load-testing protocol that includes smoke, load, stress, soak, and spike tests to re-measure request rate, error, and duration metrics.

Why should I use profiling before fixing database performance issues?

Profiling before fixing database performance issues ensures you rely on measured evidence rather than guesses, preventing wasted effort on N+1 queries or caching strategy changes.