Teaching computer science at scale can be challenging. From our experience in CS50, Harvard University’s introductory course, we’ve seen firsthand the impactful role generative artificial intelligence (Gen-AI) can play in education. Recognizing its potential and stakes, we integrated OpenAI’s GPT into our own teaching methodology. The goal was to emulate a 1:1 teacher-to-student ratio, incorporating “pedagogical guardrails” to maintain instructional integrity. The result was a personalized, AI-powered bot in the form of a friendly yellow rubber duck aimed at delivering instructional responses and troubleshooting without giving outright solutions. We plan to share our journey and offer insights into responsibly harnessing AI in educational settings. Participants will gain hands-on experience working with GPT through OpenAI’s APIs, understanding and crafting prompts, answering questions using embedding-based search, and finally, building their own AI chatbot. Ultimately, we’ll not only share lessons learned from our own approach but also equip educators hands-on with the knowledge and tools with which they, too, can implement these technologies in their unique teaching environments.