1: Porting YNAB from a spreadsheet to a C# Windows app back in 2006. (People tell us YNAB has changed their life) 2: Subsequently helping build the YNAB company/team. They are an amazing group of people and I’ll likely never be prouder of anything in my life.

To be very clear: I can’t take credit for the original idea or spreadsheet. That would be our original founder, Jesse.