It's Tuesday, 8:02am. You walk back into NoteDrop and Sasha is grinning behind two empty cold-brews. 'I let it run overnight,' he says. 'One mega-prompt against the whole Sentry backlog.' The receipt: 6 hours of wall-clock time, $80 in tokens, and one commit titled 'fix: address open issues' that touches 47 files across auth, search, billing, retry, and the seed scripts. The diff is 1,400 lines. Nobody — not you, not Sasha, not the rest of the (nonexistent) team — can review it before the investor demo, which the CEO just confirmed is in 48 hours. The marathon didn't ship work. It shipped a *trust debt* you can't pay back in two days. Today you teach Sasha what a Ralph-loop actually is: short, named, verifiable. Short loops compound. Marathons accumulate trust debt the agent can't pay back.
You'll walk out able to
- Spot the exact minute a marathon agent run started accumulating trust debt
- Pick the sprint length that fits the available failure signal, every time
- Drive an agent into emitting named kill-criteria as JSON before the loop starts
- Read a marathon-vs-Ralph commit pair and name the load-bearing process difference
- Interrupt and rescope when the agent proposes mid-loop 'while I'm here' work
- Design kill-criteria as runnable code, not as intentions
Your first task
When should you have killed Sasha's overnight run?
Sasha's tmux scrollback is still warm. He kicked the agent off at 1:47am with 'work through the Sentry backlog until you're done.' No size, no kill-criteria, no do-not-touch list. You scroll back to the start and read forward. Hour 1 looks fine. Hour 3 looks tired. Hour 5 looks like a different problem.
What you'll answer
Read the session. At which timestamp should you have killed the loop?
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