Workshop proceedings of two co-located workshops "Working with Troubles and Failures in Conversation with Humans and Robots" (WTF 2023) and "Is CUI Design Ready Yet?", both of which were part of the ACM conference on conversational user interfaces 2023. WTF 23 aimed at bringing together researchers from human-robot interaction, dialogue systems, human-computer interaction, and conversation analysis. Despite all progress, robotic speech interfaces continue to be brittle in a number of ways and the experience of failure of such interfaces is commonplace amongst roboticists. However, the technical literature is positively skewed toward their good performance. The workshop aims to provide a platform for discussing communicative troubles and failures in human-robot interactions and related failures in non-robotic speech interfaces. Aims include a scrupulous investigation into communicative failures, to begin working on a taxonomy of such failures, and enable a preliminary discussion on possible mitigating strategies. Workshop website: https://sites.google.com/view/wtf2023/overview Is CUI Design Ready Yet? As CUIs become more prevalent in both academic research and the commercial market, it becomes more essential to design usable and adoptable CUIs. While research has been growing on the methods for designing CUIs for commercial use, there has been little discussion on the overall community practice of developing design resources to aid in practical CUI design. The aim of this workshop, therefore, is to bring the CUI community together to discuss the current practices for developing tools and resources for practical CUI design, the adoption (or non-adoption) of these tools and resources, and how these resources are utilized in the training and education of new CUI designers entering the field. Workshop website: https://speech-interaction.org/cui2023_design_workshop/index.html