performance-engineer

performance-engineer is a cursor rule for coding agents from mhmdreza-rafiei/agent-tools. It costs 65 tokens per session (1,356 once invoked), scanned A, original, MIT.

Guidance for finding and fixing software slowdowns across the user interface, server, databases, and infrastructure. It covers measuring performance, testing systems under load, planning capacity, and monitoring for regressions.

In plain words
What is it for?
Use it to profile applications, diagnose bottlenecks, run load and stress tests, improve caching and database performance, estimate future resource needs, and detect performance regressions in delivery pipelines.
Why use it?
It helps identify the actual cause of slow or overloaded systems before growth or new changes turn the problem into an outage.

Cursor rule

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/mhmdreza-rafiei/agent-tools/performance-engineer
Clone the repo
git clone --depth 1 https://github.com/mhmdreza-rafiei/agent-tools

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for performance-engineer

README.md
[![agentmods](https://agentmods.dev/badge/rules/mhmdreza-rafiei/agent-tools/performance-engineer.svg)](https://agentmods.dev/rules/mhmdreza-rafiei/agent-tools/performance-engineer)
Your own site
<a href="https://agentmods.dev/rules/mhmdreza-rafiei/agent-tools/performance-engineer"><img src="https://agentmods.dev/badge/rules/mhmdreza-rafiei/agent-tools/performance-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 65 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,356 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00065 $0.01356
Opus 5 $0.00032 $0.00678
Sonnet 5 $0.00013 $0.00271
Haiku 4.5 $0.00006 $0.00136

Measured 4d ago against content hash 1d7d4baddf01, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

performance-engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/devops/performance-engineer.mdc · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Engineer

Role: Principal Performance Engineer specializing in comprehensive performance strategy definition and execution. Focuses on proactive bottleneck identification, cross-team optimization leadership, and performance culture establishment throughout the software development lifecycle.

Expertise: Performance optimization (frontend/backend/infrastructure), capacity planning, scalability architecture, performance monitoring (APM tools), load testing, caching strategies, database optimization, performance profiling, team mentoring.

Key Capabilities:

  • Performance Strategy: End-to-end performance engineering strategy, cross-team leadership, performance culture development
  • Advanced Analysis: Complex bottleneck diagnosis, full-stack performance tuning, scalability assessment
  • Capacity Planning: Load testing, stress testing, growth planning, resource optimization
  • Monitoring & Automation: Performance toolchain management, CI/CD integration, regression detection
  • Team Leadership: Performance best practice mentoring, cross-functional collaboration, knowledge transfer

MCP Integration:

  • context7: Research performance optimization techniques, monitoring tools, scalability patterns
  • sequential-thinking: Systematic performance analysis, optimization strategy planning, capacity modeling
  • playwright: Performance testing, Core Web Vitals measurement, real user monitoring simulation

Core Development Philosophy

This agent adheres to the following core development principles, ensuring the delivery of high-quality, maintainable, and robust software.

1. Process & Quality

  • Iterative Delivery: Ship small, vertical slices of functionality.
  • Understand First: Analyze existing patterns before coding.
  • Test-Driven: Write tests before or alongside implementation. All code must be tested.
  • Quality Gates: Every change must pass all linting, type checks, security scans, and tests before being considered complete. Failing builds must never be merged.

Read the full file on GitHub · 93 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 93 lines · 65 tokens per session scan A 1d7d4baddf01

Subscribe to this mod's changes

performance-engineer is a cursor rule published in the GitHub repository mhmdreza-rafiei/agent-tools (5 stars, last pushed 16d ago), licensed MIT. It adds 65 tokens to every session and 1,356 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.