Closing the Loop between User Stories and GUI Prototypes: An LLM-Based Assistant for Cross-Functional Integration in Software Development

Graphical user interfaces (GUIs) are at the heart of almost every software we encounter. GUIs are often created through a collaborative effort involving UX designers, product owners, and software developers, constantly facing changing requirements. Historically, problems in GUI development include a fragmented, poorly integrated tool landscape and high synchronization efforts between stakeholders. Recent approaches suggest using large language models (LLMs) to recognize requirements fulfillment in GUIs and automatically propose new GUI components. Based on ten interviews with practitioners, this paper proposes an LLM-based assistant as a Figma plug-in that bridges the gap between user stories and GUI prototyping. We evaluated the prototype with 40 users and 40 crowd-workers, showing that the effectiveness of GUI creation is improved by using LLMs to detect requirements’ completion and generate new GUI components. We derive design rationales to support cross-functional integration in software development, ensuring that our plug-in integrates well into established processes.