Concurrency / Complexity
Kind: tension
Record: tension:complexity-concurrency
Canonical: Schema
"concurrency" (performance-core layer) is traded against "Complexity" (human-factors layer) — a principle cannot be scope-separated from a quality, metric, or cost it competes with; resolve by measuring "Complexity" and choosing an explicit operating point.
Listed in Tensions, after Statelessness / State Access Latency and before Parallelism / Coordination Overhead.