perf

Analyze the codebase or a specific area for performance issues. Read-only analysis — report findings, don't auto-fix.

Rails (main-api)

N+1 Queries

• Find .each/.map/.find_each loops that access associations
• Check if includes/eager_load/preload is used upstream
• Check serializers with belongs_to/has_many that trigger lazy loads

Slow Queries

• Find where clauses on columns without indexes (cross-reference with db/schema.rb)
• Find LIKE/ILIKE queries without trigram/GIN indexes
• Find order on unindexed columns
• Check for pluck vs loading full objects when only IDs/values needed

Sidekiq

• Find jobs doing heavy DB work without batching
• Check for jobs that could be parallelized

Next.js (Frontend)

Re-renders

• Find components missing memo, useMemo, or useCallback where appropriate
• Check for objects/arrays created inline in JSX props (new reference each render)
• Find Context providers that re-render too many consumers

Data Fetching

• Check staleTime configuration in React Query hooks — too low = excessive refetching
• Find components that fetch data they could receive as props from a parent
• Check for waterfall requests that could be parallelized

Bundle

• Large imports that could be dynamic: import() for heavy components
• Check if heavy libraries are imported in client components unnecessarily

Report Format

Issue	Location	Severity	Suggested Fix