Microsoft has introduced Rayfin, an open-source software development kit (SDK) and command-line interface (CLI) at Build 2026, designed to streamline backend development for AI applications. This tool allows developers to define a complete application backend—including databases, business logic, and APIs—directly in code and deploy it to Microsoft Fabric, facilitating a fully managed backend environment. Shireesh Thota, Microsoft's CVP of databases, emphasized that Rayfin minimizes the manual integration typically required post-frontend development. Analysts like Stewart Bond from IDC highlight that while Rayfin boosts developer productivity, its primary value lies in governance, providing inherited security and compliance from the outset. The need for automated governance and real-time processing is becoming critical as enterprises move beyond isolated AI experiments. Rayfin's strategic significance lies in positioning Microsoft Fabric as a runtime for AI-native applications, a move that could redefine enterprise AI development. However, skepticism remains regarding developer adoption of Fabric as a runtime platform. Rayfin is currently available in preview, with a 60-day trial for enterprises.