performance-optimization

Identifies and fixes Rails performance issues including N+1 queries, slow queries, and memory problems. Use when optimizing queries, fixing N+1 issues, improving response times, or when user mentions performance, slow, optimization, or Bullet gem.

Install with Tessl CLI

npx tessl i github:ThibautBaissac/rails_ai_agents --skill performance-optimization

What are skills?

Review — 82%

Does it follow best practices?

If you maintain this skill, you can automatically optimize it using the tessl CLI to improve its score:

npx tessl skill review --optimize ./path/to/skill

Learn more

Evaluation — 89%

Agent success when using this skill

Validation — 10 / 11 Passed

Validation for skill structure

SKILL.md

Review

Evals

Evaluation results

91%

-7%

Slow Events Listing — Query Optimization

N+1 eager loading and query optimization

Criteria

Without context

With context

Uses includes for venue

100%

Uses includes for organizer

100%

No eager_load for simple associations

100%

Model scope for eager loading

100%

Counter cache on Comment

100%

Counter cache on EventVendor

100%

Migration adds counter cache columns

100%

No .count on associations in view or controller

100%

75%

pluck or select used appropriately

75%

37%

CHANGES.md explains method selection

100%

Scope used in controller

100%

Correct includes nesting syntax

100%

50%

Without context: $0.3175 · 1m 30s · 14 turns · 63 in / 4,929 out tokens

With context: $0.4076 · 1m 12s · 20 turns · 380 in / 4,044 out tokens

83%

Concert Ticket Platform — Database Migration and Bulk Data Backfill

Database indexing and batch operations

Criteria

Without context

With context

Index on user_id FK

100%

Index on show_id FK

100%

Index on venue_id FK

100%

Composite index for user+status query

100%

Partial index for active statuses

MIGRATION_NOTES explains each index

100%

Bulk update uses update_all

100%

No AR object instantiation for bulk update

100%

Script runnable via rails runner

100%

Index comment order matters

100%

No redundant single-column indexes

100%

Covering or include index considered

Without context: $0.2241 · 59s · 10 turns · 11 in / 3,239 out tokens

With context: $0.3573 · 1m 17s · 15 turns · 64 in / 3,907 out tokens

93%

Rails Performance Monitoring Infrastructure Setup

Performance monitoring tooling setup

Criteria

Without context

With context

bullet gem in dev/test group

100%

rack-mini-profiler gem present

100%

stackprof gem present

100%

Bullet dev config block

60%

100%

Bullet.raise in test env

100%

rack-mini-profiler position config

100%

rack-mini-profiler start_hidden false

100%

Slow query subscriber threshold 100ms

55%

100%

Bullet RSpec before/after hooks

100%

QueryCounter module

100%

around_action log_query_count

90%

100%

warn_on_records_fetched config

memory_profiler gem present

100%

Bullet.raise NOT in development

100%

Without context: $0.4195 · 1m 53s · 17 turns · 18 in / 6,529 out tokens

With context: $0.7894 · 2m 13s · 36 turns · 335 in / 8,145 out tokens

Evaluated: about 5 hours ago
Agent: Claude Code

Table of Contents

Slow Events Listing — Query Optimization Concert Ticket Platform — Database Migration and Bulk Data Backfill Rails Performance Monitoring Infrastructure Setup

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