Tablekeeper a four-seat dark factory

Tablekeeper is a restaurant reservation service: search availability, book a table, find the booking again by reference, amend or cancel it over time zones, daylight saving, idempotent retries, policies that change at a point in time, and seating replans that rewrite bookings without breaking their history. No human wrote any of it. It was built by a dark factory: four coding agent seats sharing one Band room. The coordinator runs the floor. The implementer writes the code and posts a handoff card carrying the revision, the claim, every command it ran with its exit code, and the whole task pasted again the seat reading it may assume nothing. Two of the four seats do nothing but check. The falsifier re runs the delivered tests five ways on its own clone: as delivered, on the last revision it accepted, with the implementation reverted, with every changed function emptied, and against the earlier stage's accepted code. The verifier builds from a third clone and tests the running service against the spec. The best thing it caught: a stage 2 revision whose suite passed exit zero and which the falsifier rejected anyway. It had diffed those tests against the stage 1 tests it had already accepted and found one quietly rewritten, with no requirement asking for the change. Nothing failed, nothing was red, and it was refused because a green suite is not evidence on its own. That is the event's own disqualifying rule, enforced by the factory on itself. All four stages were built and accepted in 9h 42m of running time on six human messages four stage dispatches and two process notes about reporting, neither touching the service. Ten verdicts, two of them rejections. Forty findings raised: five fixed, thirty-five withdrawn by the checker itself on replay. Every one of the nine commits touching a stage folder is the implementer's. No merges, no rebases. It is not magic: it stalled twice, and a second model family failed the job and was swapped back to Claude.