Mongodb Expert

This is your MongoDB specialist for when general database knowledge isn't cutting it. It handles the gnarly stuff: aggregation pipeline optimization using the ESR rule (Equality, Sort, Range), sharding strategies that actually push operations down to the shard level, and connection pool tuning beyond just bumping maxPoolSize. The embedded diagnostics are solid, from checking document sizes against the 16MB limit to finding unused indexes with $indexStats. Best for when you're past basic CRUD and dealing with performance bottlenecks, schema design decisions (embed vs reference), or replica set configuration. It covers both the MongoDB native driver and Mongoose, with specific attention to Atlas deployments.