WriteOff AI was built at the O1 Summit Hackathon in April 2026, where my teammate and I took on the challenge of making tax season less painful for freelancers and small business owners. In just 24 hours, we went from idea to a working full-stack web application. The concept was simple — many freelancers leave money on the table because they don’t track their deductible expenses properly, and we wanted to solve that with AI.

The app lets users upload their receipts and uses Groq-powered AI to analyze and categorize expenses, with Tinyfish handling the result processing and output, and deployed on Vercel. The entire project was developed using Kiro as our IDE, which helped us move fast and stay efficient under a 24-hour hackathon deadline.