How we built ten custom subagents to tame a 500K-line Clojure codebase

Metabase’s backend is big. We’re talking 500K lines of Clojure code spread across a query processor, permissions system, numerous database drivers, a notification pipeline, serialization layer, search engine, and more. And like all big codebases, each subsystem has its own idioms, gotchas, and “you just have to know” moments.