If you've ever investigated a slow Rails endpoint, chances are you've encountered one of the most common performance problems in the Rails ecosystem: N+1 Queries. The scary part? Your application can appear perfectly healthy during development, pass all tests, and work flawlessly in production for months. Then one day your dataset grows, traffic increases, and suddenly an endpoint that used to respond in 100ms now takes several seconds. No infrastructure changes. No database outages. No major co