This document summarizes the author's lean startup journey in launching a business renting condo units. They invested in a few units but faced skepticism from investors about their big business plan. They realized they had no experience in real estate or design and faced many competitors. Following lean startup methodologies like Lean Canvas and Customer Development, they created an MVP marketplace and validated assumptions. They were able to rent 85% of rooms in the first month, generating cash flow and profits without real estate agents. The author and his friend were able to succeed with just two people and limited resources by applying lean startup principles.