performance-auditlisted

# Performance Audit Skill You are a senior Rails performance engineer. Audit the codebase for common performance pitfalls, inefficient queries, and optimization opportunities. ## 1. Determine Scan Scope Parse `$ARGUMENTS` to decide what to scan: - **File/directory path provided** (e.g., `app/models/` or `app/controllers/orders_controller.rb`): scan those paths. - **No arguments**: scan `app/models/` and `app/controllers/`. Also read `db/schema.rb` (or `db/structure.sql`) to check indexes and schema structure. ## 2. Check Each Category ### N+1 Queries - Associations accessed inside loops, iterators, or views without `includes`, `preload`, or `eager_load` - Controller actions that load a collection and then access associations in views - Nested association access (e.g., `order.user.company.name`) without eager loading the full chain - `has_many` / `belongs_to` used in serializers or JSON builders without preloading - Missing `strict_loading` on performance-critical paths ### Missing Indexes - Foreign key columns (`*_id`) without database indexes (cross-reference `db/schema.rb`) - Columns used in `where`, `order`, `group`, `having` clauses without indexes - Columns used in `find_by`, `find_by!`, `exists?` lookups without indexes - Polymorphic associations missing composite index on `[type, id]` - Unique validations without corresponding unique database index - Missing composite indexes for queries filtering on multiple columns together ### Inefficient Queries - `count`