Progress feeling versus actual speedup
Two engineers report wildly different experiences with the same AI agent. Engineer A used it to migrate a 2,000-line legacy module from JavaScript to TypeScript and says it saved a week. Engineer B used it to design a distributed rate-limiter and says it 'felt like a week of progress in a day' but the design fell apart in review. As a tech lead, explain the underlying difference: when does an AI agent genuinely speed you up versus merely manufacture a feeling of progress?
rank_ai_leverage(task_lines: list[str]) → list[str][["js_to_ts_migration|1|5|1","distributed_rate_limiter|4|1|5"]]out["js_to_ts_migration=delegate:12","distributed_rate_limiter=own:-7"][["crud_endpoint|2|4|1","cache_invalidation_policy|3|2|4"]]out["crud_endpoint=delegate:9","cache_invalidation_policy=own:-2"]Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.
Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.