I build Slate, an invoicing and bookkeeping SaaS for Israeli businesses. Angular on the front, Express and Prisma on the back, Postgres underneath. The documents it issues are real fiscal records. Israeli law requires them kept for seven years, numbered without gaps, and never edited after issue. That constraint shaped every AI feature in the product. There are five of them today: receipt scanning (photo of a receipt, out comes a filled expense form), a chat assistant that answers question...