Code RoomGreenfield versus state-machine tasks
MediumPrep Room Coding #4322

Greenfield versus state-machine tasks

Vibe & agenticAlgorithms & data structuresMid–Senior~16 min

Two tasks land on your desk. Task A: 'Build a small CLI tool with arg parsing, three subcommands, tests, and a README' — greenfield, clear shape. Task B: 'Touch the billing-state machine to add a paused state, threading it through 9 call sites with subtle ordering rules.' A colleague wants to fire off an autonomous agent for both and walk away. For which task is 'launch and walk away' appropriate, and how should your supervision differ?

Implement
choose_agent_leash(touched_call_sites: int, greenfield: bool, end_to_end_verifiable: bool, money_impacting: bool) → str
Examples
in[0,true,true,false]out"launch_and_walk_away"
in[9,false,false,true]out"review_each_checkpoint"
What a strong answer looks like

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.

0:00 of about 16 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.