Conversational AI has quietly become the most intimate form of human–computer interaction we have ever built. From character.ai companions racking up billions of messages, to AI tutors that hold a child's attention longer than any app before them, talking to a machine no longer feels like science fiction - it feels routine. But behind every smooth conversation lies a stack of design decisions: how do you keep latency under the threshold where it stops feeling human? How do you let users interrupt mid-sentence? Do you bet on a single end-to-end speech model, or stitch together ASR, an LLM, and TTS like classic plumbing? In this talk we'll tour the landscape of conversational AI — its breakout applications, its risks (especially in companion and edtech use cases), and the two architectural schools fighting for the future. Then we'll roll up our sleeves and build one. Live, on a laptop, for free, walking through every block of a modern voice agent. You'll leave with a block diagram in your head, a list of swappable components, and a ready-to-code spec you can hand to Claude Code tonight to ship your own AI companion before bedtime.
Xavier Anguera is SVP of AI for Language Learning at Babbel and a recognised expert in Speech AI, Deep Learning, and Large Language Models. With more than 20 years of experience, over 100 publications, and multiple patents, he has led the development of AI systems at production scale across industry and research.
