Implementing e-invoicing is one of the most cross-functional programmes a company can undertake. It touches tax, accounting, procurement, sales, information systems and third-party master data, and now, with e-reporting obligations, data itself as a regulatory object. In this context, traditional project tools (spreadsheets, Word documents, Jira tickets, specification slides) quickly reach their limits: they artificially separate code, data, reasoning and decisions. The noteb