A dashboard request can look harmless. The problem appears when hundreds of users ask for the same expensive data at the same time. In Software Engineering Lab 04, the scenario is a workshop dashboard. Without caching, every request runs six database queries with joins and aggregations. 500 concurrent users ↓ Dashboard request ↓ 6 queries + join/aggregation per request ↓ 3000 total DB queries The first instinct is easy: put Redis in front o...