What are the three main bottlenecks that prevent parallel AI agent development, and why do they make parallelism ineffective?

The three bottlenecks are: clearly conveying requirements to the Agent, ensuring code functional correctness, and guaranteeing code maintainability. All three require deep human involvement—reviewing code, negotiating requirements, and directing architecture—turning humans into a single-point bottleneck. Since human attention is serial and limited, launching multiple Agents only creates concurrent queuing, not true parallelism. This is the core problem addressed in Parallel Development Experience Bought with Thousands of Dollars in Tokens: Let a Group of AI Agents Write Code for You.