parallelization-by-defaultlisted

# Parallelization By Default > Velocity primitive. Mandatory under Owner thesis > `feedback_owner_velocity_thesis.md`: *"sub-agent dispatch mandatory when CEO > would do work a sub-agent does equally well."* Sequential CEO Opus execution > of parallelizable work is the framework's primary failure mode. ## Fail-Fast Rule If a task contains **>=3 independent items** with no inter-item dependency cycle, CEO MUST dispatch sub-agents in parallel. Sequential CEO execution of the same items is a velocity violation and SHOULD trigger the `anti-ceo-overhead` hook (PLAN-083 sub-agent 0.5). ## When to invoke CEO consults this skill at every decision point where work is non-trivial. A task is **decomposable** (eligible for parallel dispatch) when ALL of: 1. **Item count >=3.** Two items is not worth dispatch overhead (sub-agent spin-up + prompt construction + result synthesis costs ~10-30s of wallclock). With three or more, the wallclock savings dominate. 2. **No inter-item dependency cycle.** Item B depending on Item A's output means serial. A DAG with independent leaves can still parallelize the leaves. Use sequential CEO only when the dependency graph is a chain. 3. **Each item fits in a single sub-agent prompt.** If one item would require the sub-agent itself to dispatch more sub-agents (recursive fan-out), split it into a sub-plan first; otherwise contention ceiling cascades. 4. **No shared-file write contention.** If two items would Edit/Write the same ca