Responsible AI is the practice of developing and using AI systems in a way that benefits the humans, society, and environment, while minimising the risk of negative consequences. Various responsible AI principles have been released recently. However, those principles are very abstract and not practical enough. Further, significant efforts have been put on algorithm-level solutions which are usually confined to a narrow set of principles (such as fairness and privacy). To bridge the gap, we adopt a pattern-oriented approach and build a responsible AI pattern catalogue for operationalising responsible AI from a system perspective. In this article, we first summarise the major challenges in operationalising responsible AI at scale and introduce how we use responsible AI pattern catalogue to address those challenges. Then, we discuss the case study we have conducted using the chatbot development use case to evaluate the usefulness of the pattern catalogue.