concurrency

Rapid function scaling can overwhelm a shared dependency. Concurrency limits, reserved capacity and queue buffering are the containment toolkit.

Everyone answers state locking. The follow-up is what happens when locking is not configured, and what you do with a stale lock at 2am, which is where the answer gets real.

Cost per merge beats cost per minute. Attribute spend by pipeline, attack caches and matrix sprawl first, and know what self-hosted runners really cost.