I Spent 30 Days “Vibe Coding” an MVP — Burned $127, Broke Everything, and Still Found Product-Market

I spent 30 days building a financial planning tool for founders by “vibe coding”. Made every mistake possible. Burned through $127 in Replit credits. Got calculations wrong by 20%. Watched 23 "interested" founders become 2 signups. But I also learned that: (1) AI struggles with precision calculations, (2) founders don't want another spreadsheet—they want advice, and (3) sometimes less is more. One founder offered $50/month for the simplified version. That's validation enough to keep going. This was a great learning experience for me as I go to be on the other side of the table so to say. I spend time working with founders at accelerators and advising them about getting from zero to 1. This was a good opportunity for me to “eat my own dog food”!