Google-Integrated CRM Proof of Concept

A client ran their CRM on Google Sheets and Apps Script: appointments, customers, income and expenses, Calendar events, WhatsApp templates. They wanted to turn it into a product where every user connects their own Google account. Several bidders had told them it could not be done.

The PoC proves exactly one loop, end to end: a web application signs the user in with Google OAuth, reads and writes their own Sheet, and creates events in their own Calendar. Once that loop runs, the whole product architecture is proven. The point was never to build a CRM; it was to kill the "impossible" claim in a day.