Explore voice user interfaces through Roland Tiefenbrunner's conference talk based on his extensive experience developing Alexa Skills, collaborating with Amazon experts, and facilitating workshops. Gain insights into voice interface challenges, market trends, and alternatives like Mozilla Common Voice. Learn about automatic speech recognition, intent mapping, slot value mapping, and user behavior analysis. Discover design principles for creating effective voice interactions, including keeping prompts short and following best practices. Understand the complexities of voice model development, matching rates, and the importance of user experience in voice-based applications.