OpenClosed August 9, 2026
The founder's voice note: build Lea's one-page business plan
The top entry gets featured in Ruben's Substack.
What you needClaude (a free claude.ai account is enough)Any doc tool for the one-pager: Google Docs, Notion, Gamma, your pick
Scored onFounder reality 20Numbers reconciled 20Economics that add up 20First 90 days 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 one-page business plan for Lea that a bank would read: real numbers from the case file, a 90-day start, and the honest risk. Public link or uploaded file.
The full mission and 2 case files unlock inside the challenge room. 60 minutes, one attempt, everyone works from the same case.
This challenge is closed for submissions. See the current challenge →