mongodb-indexing-and-query-optimization

Use when auditing or optimizing MongoDB query and aggregation performance for an existing data model after data-architecture and the data model exist and performance has set the query SLOs. Produces an explain("executionStats")-driven query review, an index audit (compound/multikey/text/geo/TTL/partial/wildcard), aggregation-pipeline cost review, projection and collation posture, shard-key effectiveness analysis, and profiler-driven hot-collection identification with a remediation plan. Do not use for document modeling, validator or shard-key choice, replication topology, backup, security hardening, or ODM/repository query code; use the other Family B archetype skills (modeling/shard-key is data-model-and-migration; ODM code is the backend skill).