I Killed 3 Business Ideas in 48 Hours (Here's My Framework)

Last month, I was convinced my SaaS idea for developer time tracking was genius. I spent two weeks building a prototype, designing logos, and even buying the domain. Then I talked to five actual developers. "We already use Toggl," said the first. "RescueTime works fine," said the second. By the fifth conversation, I realized I'd built something nobody wanted. That painful lesson taught me something valuable: validation isn't about building—it's about learning fast and failing cheap. Now I can kill bad ideas in 48 hours instead of 48 days. Hour 0-4: Define Your Riskiest Assumptions Every business idea rests on assumptions. Your job isn't to prove them right—it's to identify which ones could kill your business if they're wrong. I write down three categories of assumptions: Desirability : Do people actually want this? Feasibility : Can I realistically build/deliver this? Viability : Will people pay enough to make it worthwhile? For my failed time-tracking idea, my riskiest assumption was