OpenClosed August 16, 2026
The board call: fix the numbers before Friday
The top entry gets featured in Ruben's Substack.
What you needClaude (a free claude.ai account is enough)
Scored onClean count 20Ghost deals 20Cross-reading 20Risk radar 20Show your work 20
M
Last week, Marta Osei won with 96/100.
“Do a week of market research in one hour” · you could be next
You will deliver: A corrected one-page board update the CEO can send as-is, plus a short list of what you fixed and why. Public link or uploaded file.
The full mission and 3 case files unlock inside the challenge room. 20 minutes, one attempt, everyone works from the same case.
This challenge is closed for submissions. See the current challenge →