Generative AI is making it much easier to write and test code, reducing the time it takes to develop new software. The telecoms sector can harness this technology to increase the productivity of their programmers, become more responsive to demand, improve delivery efficiency and fuel innovation. This Catalyst is focused on the research and development of large language models (LLMs) in the telecoms domain, and how CSPs can apply them to harness professional knowledge across various business scenarios. By integrating LLMs into processes throughout the software development lifecycle, the Catalyst intends to reduce repetitive coding tasks, and automate code detection and the generation of test cases. The solution will also provide design suggestions, while assisting in aligning requirements with the design and implementation processes. Harnessing the TM Forum’s open digital architecture (ODA) to provide standardized interfaces, the Catalyst will use LLMs to introduce intelligent assistants into CSPs’ product marketing and service support systems. These assistants will support multimodal interactions and multi-round question-answering using natural language, while delivering a personalized service experience that will enhance customer satisfaction and service quality. For CSPs, this promises to streamline customer service operations, and enhance quality and efficiency.