Planner/Worker/Judge Triad: The Multi-Agent Architecture That Survives Lock Contention

earezki.com·high signal

Equal-status multi-agent coordination — all agents at the same level competing for shared locks — degrades predictably as lock-hold times increase and throughput drops, a failure Cursor's parallel agent users documented empirically. The validated production pattern separates three non-overlapping roles: Planners (explore codebase, decompose tasks, never execute), Workers (execute tasks with no peer coordination), and Judges (review outputs, decide continue/stop/retry). Workers never coordinate with each other — all coordination is asynchronous through Planners and Judges — eliminating the lock contention root cause.