The Sequential Refinement Trap

Senior AI Engineer interview at Google, and the interviewer asks:

“You built a sequential refinement pipeline. Agent 1 drafts, Agent 2 improves it, Agent 3 improves that. Agents 5 through 10 don’t move quality at all. Why is a chain the worst topology for scaling agent collaboration, and what’s the first structural change you’d make?”

Don’t say: “Latency. Each agent waits on the last one. Use a stronger model for each refiner and tighten the prompts.”